Functions 3 Question 9

9. Let F(x) be an indefinite integral of sin2x.

Statement I The function F(x) satisfies

F(x+π)=F(x) for all real x.

Because

Statement II sin2(x+π)=sin2x, for all real x.

(2007,3M)

Analytical & Descriptive Question

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Answer:

Correct Answer: 9. (d)

Solution:

  1. Let φ(x)=f(x)g(x)=x,xQ x,xQ

Now, to check one-one.

Take any straight line parallel to X-axis which will intersect φ(x) only at one point.

φ(x) is one-one.

To check onto

As f(x)=x,xQ x,xQ, which shows

y=x and y=x for rational and irrational values

y real numbers.

 Range = Codomain  onto 

Thus, fg is one-one and onto.



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