Answer:
C
Step-by-step explanation:
The difference formula for cosine is
cos(x - y) = cosxcosy + sinxsiny
Consider
cos75 = cos(120 - 45)°, then
cos(120 - 45)°
= cos120°cos45° + sin120°sin45° → C
-21/10 or -2&1/10 I used my calculator
(x+4)²= (x+4)×(x+4)
Use the FOIL method to simplify
F=First (multiply the first number of each expression)
O=Outside (multiply the outside edges of each expression)
I= Inside (multiply the inside edges of each expression)
L= Last (multiply the last number of each expression)
x times x= x²
x times 4= 4x
4 times x= 4x
4 times 4= 16
Add them together, we have: x²+4x+4x+16
We can simplify this by adding like terms
4x+4x=8x
Final expression= x² + 8x + 16
6+6
8+4
9+3
10+2
11+1
Hope this helps!