Question

explain this question please

Answer 1

hello friend !! here is your solution !!
hope it helped you !!
thank you !!
be Brainly !!
please mark it as brainliest answer !!☺

Answer 2

$\textbf{Solution:}$

✔You need to apply the double angle formula for the sine:

 Sin(2A) = 2sin(A)cos(A)

Since sin(A)= 4/5

Sin(2A) = 2×4/5×cos(A)

sin (2A) = 8/5 cos(A)

To find cos (A) , use Pythagorean identity;

$sin {}^{2} (a) + cos {}^{2} (a) = 1 \\ \\ cos {}^{2} (a) = 1 - sin {}^{2} (a) \\ \\ cos {}^{2} (a) = 1 - ( \frac{4}{5 } ) {}^{2} \\ \\ cos {}^{2} (a) = \frac{9}{25} \\ \\ cos (a) = \sqrt{ \frac{9}{25} } = \frac{3}{5}$

So,

$sin(2a) = \frac{8}{5} \times \frac{3}{5} = \frac{24}{25}$

Hence, the final answer is  ± 24/25.

$\textbf{Thank you!!}$