Question

How do you evaluate `sin[2cos^(-1)(3/5)]`?

Answer 1

`+-24/25=+-0.96`.

Explanation:

Let `a = cos^(-1)(3/5)`. Then `cos a = 3/5>0`.. So,a is in the 1st or un

the 4th quadrant. Accordingly, `sin a = +-4/5`.

Now, the given sine is `sin 2a = 2 sin a cos a=2(+-4/5)(3/5)=+-24/25`..