5cos (2x)+7=cos (2x)+8, 4cos (2x)=1, cos (2x)=1/4, 2x=arccos(1/4), x=(1/2)arccos (1/4). I used x instead of theta, and arccos is cos inverse
2, he answer is 2 do not question my answer
Answer: (-5, -3)
Step-by-step explanation:
(-10, -6)
-10/2 = -5
-6/2 = -3
Bu using Pythagoras theorem
(x^2)+(21)^2=(75)^2
Therefore. 5625-441=(x)^2
X^2=5184
Therefore x=72
Third side length=72 units