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

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Answer 1 · 2016-05-18T16:30:37

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

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 $sin 2a = 2 sin a cos a=2(+-4/5)(3/5)=+-24/25$ ..

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