What is sinx?

The sine function, often abbreviated as sin(x), is a fundamental trigonometric function that plays a crucial role in various mathematical and scientific applications. It is defined as the ratio of the length of the opposite side to the length of the hypotenuse in a right-angled triangle, where x represents the angle opposite to the opposite side.

Properties of Sine Function

The sine function exhibits several important properties that make it useful in various mathematical operations:

• Periodicity: The sine function is periodic with a period of 2π. This means that sin(x + 2π) = sin(x) for any real number x.
• Symmetry: The sine function is an odd function, which means that sin(-x) = -sin(x).
• Range: The range of the sine function is between -1 and 1, i.e., -1 ≤ sin(x) ≤ 1.
• Zeros: The sine function has an infinite number of zeros at x = nπ, where n is any integer.

Applications of Sine Function

The sine function finds applications in numerous fields, including:

• Calculus: The sine function is essential in calculus for studying derivatives, integrals, and Taylor series expansions.
• Physics: The sine function is used to describe various phenomena, such as the motion of objects in simple harmonic motion and the behavior of waves.
• Engineering: The sine function is employed in electrical engineering, mechanical engineering, and other engineering disciplines to analyze and design systems involving periodic motion or oscillations.
• Computer Graphics: The sine function is used in computer graphics to generate smooth curves, animations, and 3D transformations.
• Signal Processing: The sine function is utilized in signal processing for analyzing and manipulating audio, video, and other types of signals.

The sine function is a fundamental mathematical tool that has a wide range of applications in various fields. Its properties, such as periodicity, symmetry, and range, make it a versatile function for modeling and analyzing periodic phenomena. Understanding the sine function is essential for gaining a deeper comprehension of mathematics, physics, engineering, and other scientific disciplines.

What is Derivative of Sinx?

The derivative of sinx is cosx. This can be proven using the limit definition of the derivative.

Limit Definition of the Derivative

The derivative of a function f(x) is defined as the limit of the slope of the secant lines to the graph of f(x) as the second point approaches the first point. In other words,

$$f’(x) = \lim_{h\to 0} \frac{f(x+h) - f(x)}{h}$$

Applying the Limit Definition to Sinx

To find the derivative of sinx, we need to evaluate the limit of the slope of the secant lines to the graph of sinx as the second point approaches the first point.

Let $f(x) = \sin x$. Then,

$$f’(x) = \lim_{h\to 0} \frac{\sin(x+h) - \sin x}{h}$$

We can use the sum-to-product formula for sine to rewrite the numerator as follows:

$$\sin(x+h) - \sin x = 2\cos\left(\frac{x+h+x}{2}\right)\sin\left(\frac{x+h-x}{2}\right)$$

Simplifying the expression, we get:

$$\sin(x+h) - \sin x = 2\cos\left(\frac{x+h}{2}\right)\sin\left(\frac{h}{2}\right)$$

Substituting this expression into the limit, we get:

$$f’(x) = \lim_{h\to 0} \frac{2\cos\left(\frac{x+h}{2}\right)\sin\left(\frac{h}{2}\right)}{h}$$

We can now use the fact that $\lim_{h\to 0} \frac{\sin h}{h} = 1$ to evaluate the limit.

$$f’(x) = \lim_{h\to 0} 2\cos\left(\frac{x+h}{2}\right)\lim_{h\to 0} \frac{\sin\left(\frac{h}{2}\right)}{\frac{h}{2}}$$

$$f’(x) = 2\cos\left(\frac{x+0}{2}\right)\cdot 1 = 2\cos x$$

Derivative of Sinx Formula

The derivative of sinx is cosx. This can be proven using the limit definition of the derivative.

Limit Definition of the Derivative

The derivative of a function f(x) is defined as the limit of the slope of the secant lines to the graph of f(x) as the second point approaches the first point. In other words,

$$f’(x) = \lim_{h\to 0} \frac{f(x+h) - f(x)}{h}.$$

Applying the Limit Definition to Sinx

To find the derivative of sinx, we need to evaluate the limit of the slope of the secant lines to the graph of sinx as the second point approaches the first point.

Let $f(x) = \sin x$. Then,

$$f’(x) = \lim_{h\to 0} \frac{\sin(x+h) - \sin x}{h}.$$

We can use the sum-to-product formula for sine to rewrite the numerator as follows:

$$\sin(x+h) - \sin x = 2\cos\left(\frac{x+h+x}{2}\right)\sin\left(\frac{x+h-x}{2}\right).$$

Simplifying the expression, we get:

$$\sin(x+h) - \sin x = 2\cos\left(\frac{x+h}{2}\right)\sin\left(\frac{h}{2}\right).$$

Substituting this expression into the limit, we get:

$$f’(x) = \lim_{h\to 0} \frac{2\cos\left(\frac{x+h}{2}\right)\sin\left(\frac{h}{2}\right)}{h}.$$

We can now use the fact that $\lim_{h\to 0} \frac{\sin h}{h} = 1$ to simplify the limit:

$$f’(x) = \lim_{h\to 0} 2\cos\left(\frac{x+h}{2}\right)\lim_{h\to 0} \frac{\sin\left(\frac{h}{2}\right)}{\frac{h}{2}}.$$

The first limit is equal to $\cos x$, and the second limit is equal to 1. Therefore,

$$f’(x) = 2\cos x \cdot 1 = 2\cos x.$$

The derivative of sinx is cosx. This can be proven using the limit definition of the derivative.

Derivative of Sinx Proof by the First Principle

The derivative of sinx can be proven using the first principle of derivatives. The first principle states that the derivative of a function f(x) is defined as:

$$f’(x) = \lim\limits_{h\to 0} \frac{f(x+h) - f(x)}{h}$$

We can use this definition to find the derivative of sinx.

Proof:

Let $$f(x) = \sin x$$. Then,

$$f(x+h) = \sin (x+h)$$

and

$$f(x) = \sin x$$

So,

$$f(x+h) - f(x) = \sin (x+h) - \sin x$$

We can use the sum-to-product formula for sine to rewrite this as:

$$f(x+h) - f(x) = 2\cos\left(\frac{x+h+x}{2}\right)\sin\left(\frac{x+h-x}{2}\right)$$

Simplifying this, we get:

$$f(x+h) - f(x) = 2\cos\left(\frac{x+h}{2}\right)\sin\left(\frac{h}{2}\right)$$

Now, we can take the limit of this expression as h approaches 0. We get:

$$\lim\limits_{h\to 0} \frac{f(x+h) - f(x)}{h} = \lim\limits_{h\to 0} \frac{2\cos\left(\frac{x+h}{2}\right)\sin\left(\frac{h}{2}\right)}{h}$$

We can use the fact that $$\lim\limits_{h\to 0} \cos\left(\frac{x+h}{2}\right) = \cos x$$ and $$\lim\limits_{h\to 0} \frac{\sin\left(\frac{h}{2}\right)}{\frac{h}{2}} = 1$$

to simplify this expression. We get:

$$\lim\limits_{h\to 0} \frac{f(x+h) - f(x)}{h} = \cos x \cdot 1 = \cos x$$

Therefore, the derivative of sinx is cosx.

Derivative of Sinx Proof by the Chain Rule

The derivative of sin(x) can be found using the chain rule. The chain rule states that if we have a function f(x) = g(h(x)), then the derivative of f(x) with respect to x is given by:

$$f’(x) = g’(h(x)) \cdot h’(x)$$

In this case, we have f(x) = sin(x) and h(x) = x. So, g(x) = sin(x) and g’(x) = cos(x).

Substituting these values into the chain rule, we get:

$$f’(x) = cos(x) \cdot 1 = cos(x)$$

Therefore, the derivative of sin(x) is cos(x).

Proof:

Let $$y = \sin x$$

Then, $$u = x$$

So, $$\frac{dy}{du} = \cos u$$

and $$\frac{du}{dx} = 1$$

By the chain rule, we have:

$$\frac{dy}{dx} = \frac{dy}{du} \cdot \frac{du}{dx}$$

Substituting the values of $\frac{dy}{du}$ and $\frac{du}{dx}$, we get:

$$\frac{dy}{dx} = \cos u \cdot 1 = \cos x$$

Therefore, the derivative of sin(x) is cos(x).

Derivative of Sinx Proof by the Quotient Rule

Introduction In this article, we will prove the derivative of the sine function using the quotient rule. The quotient rule states that the derivative of a quotient of two functions $f(x)$ and $g(x)$ is given by:

$$h’(x) = \frac{g(x)f’(x) - f(x)g’(x)}{g(x)^2}$$

Proof Let $f(x) = \sin(x)$ and $g(x) = \cos(x)$. Then, the derivative of $h(x) = \frac{\sin(x)}{\cos(x)}$ is given by:

$$h’(x) = \frac{\cos(x)(\cos(x)) - \sin(x)(-\sin(x))}{\cos(x)^2}$$

Simplifying this expression, we get:

$$h’(x) = \frac{\cos^2(x) + \sin^2(x)}{\cos^2(x)}$$

Since $\cos^2(x) + \sin^2(x) = 1$, we can simplify this further to:

$$h’(x) = \frac{1}{\cos^2(x)}$$

Therefore, the derivative of $\sin(x)$ is $\frac{1}{\cos^2(x)}$.

In this article, we have proven the derivative of the sine function using the quotient rule. This proof is a straightforward application of the quotient rule, and it demonstrates how the quotient rule can be used to find the derivatives of other trigonometric functions.

LIATE Rule

The LIATE rule is a method for determining the order of precedence of operations in mathematical expressions. It stands for “Left to Right, Inside to Outside, Exponents Last”.

Order of Operations

The LIATE rule states that operations should be performed in the following order:

1. Left to Right: Operations should be performed from left to right.
2. Inside to Outside: Operations within parentheses or brackets should be performed before operations outside.
3. Exponents Last: Exponents should be performed last.

Examples

Here are some examples of how the LIATE rule is applied:

• Example 1: 5 + 3 * 2

First, we perform the multiplication operation inside the parentheses 5 + 3 * 2 = 5 + 6

Then, we perform the addition operation from left to right: 5 + 6 = 11

• Example 2: (5 + 3) * 2

First, we perform the operations inside the parentheses: (5 + 3) * 2 = 8 * 2

Then, we perform the multiplication operation:

8 * 2 = 16

• Example 3:

$5^2$ + 3 * 2

First, we perform the exponent operation:

$5^2$ + 3 * 2 = 25 + 3 * 2

Then, we perform the multiplication operation:

25 + 3 * 2 = 25 + 6

Finally, we perform the addition operation:

25 + 6 = 31

The LIATE rule is a simple and easy-to-remember method for determining the order of precedence of operations in mathematical expressions. By following the LIATE rule, you can ensure that you are performing operations in the correct order and getting the correct results.

Nth derivative of Sinx

c

The nth derivative of sinx can be expressed using the following formula:

$$f^{(n)} (x) = \sin(x + \frac{n\pi}{2})$$

Where:

• $f^{(n)} (x)$ is the nth derivative of sinx.
• $n$ is a positive integer.

Proof:

We can prove this formula using mathematical induction.

Base Case:

When $n = 1$, the first derivative of sinx is cosx, which is equal to $\sin(x + \frac{\pi}{2})$.

Inductive Hypothesis:

Assume that the formula is true for some positive integer $k$. That is, assume that $f^{(k)} (x) = \sin(x + \frac{k\pi}{2})$.

Inductive Step:

We need to show that the formula is also true for $k + 1$. That is, we need to show that $f^{(k + 1)} (x) = \sin(x + \frac{(k + 1)\pi}{2})$.

Using the chain rule, we have:

$$f^{(k + 1)} (x) = \frac{d}{dx} f^{(k)} (x)$$

$$= \frac{d}{dx} \sin(x + \frac{k\pi}{2})$$

$$= \cos(x + \frac{k\pi}{2})$$

$$= \sin(x + \frac{k\pi}{2} + \frac{\pi}{2})$$

$$= \sin(x + \frac{(k + 1)\pi}{2})$$

Therefore, the formula is true for $k + 1$.

By mathematical induction, the formula is true for all positive integers $n$.

Examples:

• The first derivative of sinx is cosx, which is equal to $\sin(x + \frac{\pi}{2})$.
• The second derivative of sinx is -sinx, which is equal to $\sin(x + \pi)$.
• The third derivative of sinx is -cosx, which is equal to $\sin(x + \frac{3\pi}{2})$.

Anti-Derivative of sin x

Finding the Anti-Derivative of sin x

To find the anti-derivative of sin x, we can use the power rule of integration. The power rule states that the anti-derivative of $x^n$ is $(1/(n+1))x^{(n+1)} + C$, where C is the constant of integration.

In this case, n = 1, so the anti-derivative of sin x is:

$$∫ sin x\ dx = (-1/cos x) + C$$

Explanation

The power rule of integration works by finding the derivative of the anti-derivative. In this case, the derivative of (-1/cos x) is sin x, which is the original function.

The constant of integration, C, is added to the anti-derivative because the derivative of a constant is always zero. This means that there are an infinite number of anti-derivatives for any given function, each of which differs by a constant.

Example

To find the anti-derivative of sin x + 2x, we can use the power rule of integration to find the anti-derivative of each term separately. The anti-derivative of sin x is (-1/cos x), and the anti-derivative of 2x is x^2. Adding these two anti-derivatives together, we get:

$$∫ (sin x + 2x) dx = (-1/cos x) + x^2 + C$$

where C is the constant of integration.

Solved Examples on Derivative of sin x

Example 1: Find the derivative of sin(3x).

Solution:

Using the chain rule, we have:

$$f’(x) = \frac{d}{dx} \sin(3x) = \cos(3x) \frac{d}{dx} (3x) = 3\cos(3x).$$

Example 2: Find the derivative of $sin^2(x)$.

Solution:

Using the chain rule and the power rule, we have:

$$f’(x) = \frac{d}{dx} \sin^2(x) = 2\sin(x) \frac{d}{dx} \sin(x) = 2\sin(x) \cos(x).$$

Example 3: Find the derivative of sin(x) + cos(x).

Solution:

Using the sum rule, we have:

$$f’(x) = \frac{d}{dx} \sin(x) + \frac{d}{dx} \cos(x) = \cos(x) - \sin(x).$$

Example 4: Find the derivative of sin(x) / cos(x).

Solution:

Using the quotient rule, we have:

$$f’(x) = \frac{\cos(x) \frac{d}{dx} \sin(x) - \sin(x) \frac{d}{dx} \cos(x)}{\cos^2(x)} = \frac{\cos^2(x) + \sin^2(x)}{\cos^2(x)} = 1 + \tan^2(x).$$

Example 5: Find the derivative of $sin(x^2)$.

Solution:

Using the chain rule, we have:

$$f’(x) = \frac{d}{dx} \sin(x^2) = \cos(x^2) \frac{d}{dx} (x^2) = 2x\cos(x^2).$$

Derivative of Sin X FAQs

What is the derivative of sin x?

The derivative of sin x is cos x. This means that the rate of change of sin x with respect to x is cos x.

How do you find the derivative of sin x?

There are a few ways to find the derivative of sin x. One way is to use the definition of the derivative. The derivative of a function f(x) is defined as the limit of the difference quotient as h approaches 0:

$$f’(x) = \lim_{h\to 0} \frac{f(x+h) - f(x)}{h}$$

Using this definition, we can find the derivative of sin x as follows:

$$\sin’(x) = \lim_{h\to 0} \frac{\sin(x+h) - \sin(x)}{h}$$

We can use the sum-to-product formula for sine to simplify the numerator of this expression:

$$\sin(x+h) - \sin(x) = 2\cos\left(\frac{x+h+x}{2}\right)\sin\left(\frac{x+h-x}{2}\right)$$

Substituting this into the difference quotient, we get:

$$\sin’(x) = \lim_{h\to 0} \frac{2\cos\left(\frac{x+h+x}{2}\right)\sin\left(\frac{h}{2}\right)}{h}$$

We can now use the fact that $$\lim_{h\to 0} \frac{\sin(h)}{h} = 1$$

to simplify this expression further:

$$\sin’(x) = \lim_{h\to 0} 2\cos\left(\frac{x+h+x}{2}\right)\cdot 1$$

Since $$\lim_{h\to 0} \cos\left(\frac{x+h+x}{2}\right) = \cos(x)$$

we get:

$$\sin’(x) = 2\cos(x)$$

What is the derivative of sin x in radians?

The derivative of sin x in radians is also cos x. This is because the radian measure of an angle is defined as the length of the arc of a circle of radius 1 that subtends that angle. Since the circumference of a circle of radius 1 is 2π, the radian measure of an angle is equal to the angle in degrees divided by 180/π. Therefore, the derivative of sin x in radians is:

$$\sin’(x) = \frac{d}{dx} \sin(x\cdot \frac{180}{\pi}) = \cos(x\cdot \frac{180}{\pi}) \cdot \frac{180}{\pi} = \cos(x)$$

What is the derivative of sin x with respect to y?

The derivative of sin x with respect to y is 0. This is because sin x is a function of x only, and y does not appear in the function. Therefore, the derivative of sin x with respect to y is:

$$\frac{d}{dy} \sin(x) = 0$$

What is the derivative of $sin(x^2)$?

The derivative of $sin(x^2)$ is $2x\hspace{1mm}cos(x^2)$. This can be found using the chain rule, which states that the derivative of a composite function is the product of the derivatives of the individual functions. In this case, the outer function is sin(u) and the inner function is $u = x^2$. Therefore, the derivative of $sin(x^2)$ is:

$$\frac{d}{dx} \sin(x^2) = \cos(x^2) \cdot \frac{d}{dx} x^2 = 2x \cos(x^2)$$

What is the derivative of sin(x) + cos(x)?

The derivative of $sin(x) + cos(x)\hspace{1mm} is\hspace{1mm} cos(x) - sin(x)$. This can be found using the sum rule, which states that the derivative of a sum of functions is the sum of the derivatives of the individual functions. In this case, the two functions are sin(x) and cos(x). Therefore, the derivative of sin(x) + cos(x) is:

$$\frac{d}{dx} (\sin(x) + \cos(x)) = \frac{d}{dx} \sin(x) + \frac{d}{dx} \cos(x) = \cos(x) - \sin(x)$$