Question

what is the cos 30°?

Answer 1

Its (sqrt(3))/2
Hope it helps.

Answer 2

Answer:

cos 30 = $\frac{\sqrt{3} }{2}$

Step-by-step explanation:

We know that in a right triangle, the length of an opposite side of 30 degrees  is half of the length of hypotenuse.

Let "d" is the hypotenuse of the right triangle.

The opposite side = d ÷ 2

Using the Pythagorean theorem, we can find the third side.

$Thirdside^2 = d^2 - (\frac{d}{2}) ^{2}$

= $d^2 - \frac{d^2}{4}$

= $(\frac{4d^2 - d^2}{4} )$

= $\frac{3d^2}{4}$

Taking square root on both sides, we get

Third side = $\frac{\sqrt{3} d}{2}$

d is the hypotenuse. So

$\frac{\sqrt{3} }{2} = \frac{Thirdside}{Hypotenuse}$

Here third side is the Adjacent side.

So, cos 30 = $\frac{\sqrt{3} }{2}$