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!
Answer:
the answer is ( x-9) (x+1) = 0
Step-by-step explanation:
more to the solution is x= -1, 9
Answer:
Slope = -3/4
y-intercept = 2
Step-by-step explanation:

Answer:
Step-by-step explanation:
Part A: You can only use Pythagorean's Theorem on a right triangle.
Part B: The side across from the right angle is the hypotenuse. It has a length of 15.
Part C: To find the missing side using Pythagorean's Theorem:
and
and
and
a = 10.20