Answer:
x² - 8x + 20
= x²- 2*4*x + 16 + 4
= x²- 2*4*x + 4² + 4
= (x - 4)² + 4
= (x - a)² + a, with a = 4
Hope this helps!
19 x 4 is the equation and the answers is 76
The expression is:
cos (π / 5) cos (π/7) + sin (π/5) sin(π/7)
This expression can be reduced into a trigonometric function with one angle if we make use of the trigonometric identities. The appropriate identity is:
cos (A - B) = cos A cos B + sin A sin B
If we let
A = π / 5
B = π / 7
Therefore,
cos (π / 5) cos (π/7) + sin (π/5) sin(π/7) = cos (π/5 - π/7) = cos (2π/35)
