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
:


We have

In order to obtain easily the table, we need to clear y

then we evaluate for values of x
if x=0
y=-4(0)+1=1
y=1
if x=1
y=-4(1)+1=-3
y=3
if x=2
y=-4(2)+1=-7
y=-7
if x=3
y=-4(3)+1=-11
y=-11
So the table for the given equation is
x y
0 1
1 -3
2 -7
3 -11
Answer:
35x+12
Step-by-step explanation:
1. You combine like terms. (15x *3x=35x)
2.You Multiply other terms (2*6= 12)
3. Answer: 35x+12
8*(1/x) = 4*(1/8)
8/x = 4/8
64 = 4x
x = 16
Yes 1.999 is an <span>irrational number</span>