Answer:
09
Step-by-step explanation:
34
So to solve problems like these you can work out each equation by substituting the x and y with the coords from the vertex (2,-4) and which ever one is true is the corresponding equation.
Lets try the first one
A) y = 2( x-2)^2-4 this would become
-4 = 2(2-2)^2-4 we solve this and get
-4 = 2(0)-4
-4 = -4
so it seems like A is the correct answer, of course we'd wanna check out the other answers just to be sure.
Lets try one and do C
C) -2 = 2(-4-2)^2+2
-2 = 2(-8)^2+2
-2 = 130
These aren't equal so this can't be our equation
So you can also do one more just to be super sure you have the right answer but I think A is the correct one :)
4 sin^2 θ + 13cos^2 θ = 7
sin^2 θ = 1 - cos^ θ
4 - 4cos^2 θ + 13cos^2 θ = 7
9cos^2 θ = 3
cos^2 θ = 1/3
cos θ = # (1/3) # - square root
Square root of (1/3) has +1/3 and -1/3 as values of cos
Find the key angle by doing the cos inverse of #1/3
K.A = cos^-1 #(1/3) = 0.955
θ lies in all 4 quadrants
The values of θ are:
θ = 0.955, 2.186, 4.096, 7.23
Ignore 0.955, 2.186, 4.096, 7.23 as they are out of range pi/2 = 1.571
The the value of θ = 0.955 = 0.96 (to 2 d.p) radian
Hope it helped!
