Question

if sin 3/5 then find the value of cos​

Answer 1

$\sin(a) = \frac{3}{5}$

$\sin(a) = \frac{perpendicular}{hypotenuse}$

Let the perpendicular be 3x and hypotenuse be 5x

$(5x)^{2} = (3x)^{2} + base ^{2}$

$25x^{2} - 9x^{2} = base^{2}$

$16x {}^{2} = base^{2}$

$base = 4x$

$\cos(a) = \frac{base}{hypotenuse}$

$\cos(a) = \frac{4x}{5x}$

$\cos(a) = \frac{4}{5}$