Answer:
#1 is 28
Step-by-step explanation:
Set the perimeters equal, as 6x - 2 = 8x - 12, solve for x = 5, and plug in.
Answer:
15
Step-by-step explanation:
its the same as the other angle on there
Answer:
Step-by-step explanation:
![\cos(2x) = \cos^2 x-\sin^2 x = 1-2\sin^2 x \\ \\ \cos(x) = 1-2\sin^2 (\frac{x}{2}) \\ \\ \Rightarrow \sin^2 (\frac{x}{2}) = \dfrac{1-\cos(x)}{2}\\ \\ \sin(\frac{x}{2}) = \pm \sqrt{\dfrac{1-\cos(x)}{2}},\quad x\in [\frac{3\pi }{2},\pi] \Rightarrow \frac{x}{2}\in [\frac{3\pi}{4},\frac{\pi}{2}]\\ \\ \Rightarrow \sin(\frac{x}{2}) > 0 \Rightarrow \sin(\frac{x}{2}) = \sqrt{\dfrac{1-(-\frac{3}{5})}{2}} \Rightarrow \sin(\frac{x}{2}) = \sqrt{\dfrac{8}{10}}=\dfrac{2\sqrt 2}{\sqrt{10}} = \\ \\ =\dfrac{2\sqrt 5}{5}](https://tex.z-dn.net/?f=%5Ccos%282x%29%20%3D%20%5Ccos%5E2%20x-%5Csin%5E2%20x%20%3D%201-2%5Csin%5E2%20x%20%5C%5C%20%5C%5C%20%5Ccos%28x%29%20%3D%201-2%5Csin%5E2%20%28%5Cfrac%7Bx%7D%7B2%7D%29%20%5C%5C%20%5C%5C%20%5CRightarrow%20%5Csin%5E2%20%28%5Cfrac%7Bx%7D%7B2%7D%29%20%3D%20%5Cdfrac%7B1-%5Ccos%28x%29%7D%7B2%7D%5C%5C%20%5C%5C%20%5Csin%28%5Cfrac%7Bx%7D%7B2%7D%29%20%3D%20%5Cpm%20%5Csqrt%7B%5Cdfrac%7B1-%5Ccos%28x%29%7D%7B2%7D%7D%2C%5Cquad%20x%5Cin%20%5B%5Cfrac%7B3%5Cpi%20%7D%7B2%7D%2C%5Cpi%5D%20%5CRightarrow%20%5Cfrac%7Bx%7D%7B2%7D%5Cin%20%5B%5Cfrac%7B3%5Cpi%7D%7B4%7D%2C%5Cfrac%7B%5Cpi%7D%7B2%7D%5D%5C%5C%20%5C%5C%20%5CRightarrow%20%5Csin%28%5Cfrac%7Bx%7D%7B2%7D%29%20%3E%200%20%5CRightarrow%20%5Csin%28%5Cfrac%7Bx%7D%7B2%7D%29%20%3D%20%5Csqrt%7B%5Cdfrac%7B1-%28-%5Cfrac%7B3%7D%7B5%7D%29%7D%7B2%7D%7D%20%5CRightarrow%20%5Csin%28%5Cfrac%7Bx%7D%7B2%7D%29%20%3D%20%5Csqrt%7B%5Cdfrac%7B8%7D%7B10%7D%7D%3D%5Cdfrac%7B2%5Csqrt%202%7D%7B%5Csqrt%7B10%7D%7D%20%3D%20%5C%5C%20%5C%5C%20%3D%5Cdfrac%7B2%5Csqrt%205%7D%7B5%7D)
Answer:
its B ITHINK
Step-by-step explanation:
