Answer:
x = -56
Step-by-step explanation:
x/7 = -8
Multiply each side by 7
x/7 *7 = -8*7
x = -56
Answer:
2520
Step-by-step explanation:
Answer:
Step-by-step explanation:
cos (x/2)=cos x+1
cos (x/2)=2cos ²(x/2)
2 cos²(x/2)-cos (x/2)=0
cos (x/2)[2 cos (x/2)-1]=0
cos (x/2)=0=cos π/2,cos (3π/2)=cos (2nπ+π/2),cos(2nπ+3π/2)
x/2=2nπ+π/2,2nπ+3π/2
x=4nπ+π,4nπ+3π
n=0,1,2,...
x=π,3π
or x=180°,540°,...
180°∈[0,360]
so x=180°
or
2cos(x/2)-1=0
cos (x/2)=1/2=cos60,cos (360-60)=cos 60,cos 300=cos (360n+60),cos (360n+300)
x/2=360n+60,360n+300
x=720n+120,720n+300
n=0,1,2,...
x=120,300,840,1020,...
only 120° and 300° ∈[0,360°]
Hence x=120°,180°,300°
Answer:
y=-5/3x+20
Step-by-step explanation:
Let the equation of the required line be represented as ![\[y=mx+c\]](https://tex.z-dn.net/?f=%5C%5By%3Dmx%2Bc%5C%5D)
This line is perpendicular to the line ![\[y=\frac{3}{5}x+10\]](https://tex.z-dn.net/?f=%5C%5By%3D%5Cfrac%7B3%7D%7B5%7Dx%2B10%5C%5D)
![\[=>m*\frac{3}{5}=-1\]](https://tex.z-dn.net/?f=%5C%5B%3D%3Em%2A%5Cfrac%7B3%7D%7B5%7D%3D-1%5C%5D)
![\[=>m=\frac{-5}{3}\]](https://tex.z-dn.net/?f=%5C%5B%3D%3Em%3D%5Cfrac%7B-5%7D%7B3%7D%5C%5D)
So the equation of the required line becomes ![\[y=\frac{-5}{3}x+c\]](https://tex.z-dn.net/?f=%5C%5By%3D%5Cfrac%7B-5%7D%7B3%7Dx%2Bc%5C%5D)
This line passes through the point (15.-5)
![\[-5=\frac{-5}{3}*15+c\]](https://tex.z-dn.net/?f=%5C%5B-5%3D%5Cfrac%7B-5%7D%7B3%7D%2A15%2Bc%5C%5D)
![\[=>c=20\]](https://tex.z-dn.net/?f=%5C%5B%3D%3Ec%3D20%5C%5D)
So the equation of the required line is ![\[y=\frac{-5}{3}x+20\]](https://tex.z-dn.net/?f=%5C%5By%3D%5Cfrac%7B-5%7D%7B3%7Dx%2B20%5C%5D)
Among the given options, option 4 is the correct one.
