What is the vertex of the graph of y = x2 + 4x?

 the answer is  ( − 2 , − 4 ) or the answer could be this y=(x+2)^2 - 4

Step-by-step explanation:

For the answer to the question above, If cos Θ = square root 2 over 2 and 3 pi over 2 < Θ < 2π, what are the values of sin Θ and tan Θ? 

If 3 pi over 2 < Θ < 2π Then the signs of sinx and tanx are both negative. 

cos(x) = sqrt(2)/2. So sin(x) = -sqrt(2)/2 and tan(x) = -1. 

sin Θ = square root 2 over 2; tan Θ = −1 

sin Θ = negative square root 2 over 2; tan Θ = 1 

sin Θ = square root 2 over 2; tan Θ = negative square root 2 

sin Θ = negative square root 2 over 2; tan Θ = −1