Given:
To find:
The exact value of cos 15°.
Solution:
Using half-angle identity:
Using the trigonometric identity: 
Let us first solve the fraction in the numerator.
Using fraction rule: 
Apply radical rule: ![\sqrt[n]{\frac{a}{b}}=\frac{\sqrt[n]{a}}{\sqrt[n]{b}}](https://tex.z-dn.net/?f=%5Csqrt%5Bn%5D%7B%5Cfrac%7Ba%7D%7Bb%7D%7D%3D%5Cfrac%7B%5Csqrt%5Bn%5D%7Ba%7D%7D%7B%5Csqrt%5Bn%5D%7Bb%7D%7D)
Using 
:
First, you need to know what a complementary angles are.
They are two angles that add up to 90 degrees.
If the number multiplied by 2 is 90, just to 90/2.
This gives you 45
Answer:
It's all about the brackets.
Step-by-step explanation:
If we do (-4)^2, the brackets make it -4 x -4 and the two negatives make a positive of 16.
If we do -4^2, that means that the 4 is squared before putting the minus sign there so you have 4x4 = 16 then put the minus to get -16.
Hope this helps!
treviglaslibrary
It is 16 because 3x16=48 and 4x16=64!
