Just subsitute 8 for n
1/2(8)^2-1/2(8)
1/2(64)-4
32-4
28
D
Answer:
x^2 - 2xy + y^2.
Step-by-step explanation:
(x - y)^2
= (x - y)(x - y)
= x(x -y) - y(x - y)
= x^2 - xy - xy + y^2
= x^2 - 2xy + y^2.
Answer:
d
Step-by-step explanation:
First you must know that for remarkable angles: cos (0) = 1, cos (π) = - 1, cos (π / 2) = 0, cos (3π / 2) = 0, cos (2π) = 1. Then, by simple substitution in the given formula, you can find the solutions of x. Which for the interval [0, 2π) are: x = π, x = pi divided by two and x = three pi divided by two.Attached solution.