Take the natural log of both sides
ln(2^x)=ln(.125)
Xln(2)=ln(.125)
X=ln(.125)/ln(2)
X=-3
ALTERNATIVE ROUTE:
You know that 0.125 is equal to 1/8
And 1/2^3 is also equal to 1/8
So since you need the reciprocal to match it the exponent is a negative
Answer:
45,135,315,225
Step-by-step explanation:
2cos^2x = 1
Divide each side by 2
cos^2x = 1/2
Take the square root of each side
sqrt( cos^2 x) = ±sqrt (1/2)
cos x =±sqrt (1/2)
Make into two separate equations
cos x =sqrt (1/2) cos x = - sqrt(1/2)
Take the inverse cos of each side
cos ^-1 cos (x) = cos ^-1 (sqrt (1/2)) cos ^-1 cos (x) = cos ^-1 (-sqrt (1/2))
x = cos ^-1 (sqrt (1/2)) x = cos ^-1 (-sqrt (1/2))
x = 45 +360 n x = 135+ 360n
x = 315+360 n x =225+360n
Between 0 and 360
45,135,315,225
The exact name of the postulate isn't coming to mind, but it's the postulate that any three points that are not on the same line will form a unique plane. A plane in mathematics is a flat surface that extends in all directions.