As a rule option A is the answer to a degree
Answer:
r = 7
Step-by-step explanation:
Use the distributive property by multipling the -8 to the 2r and the -8, do the same thing on the other side with the -3.
Afterwards, combine like terms by adding 64 and 6.
Next, add 3r to the left side, I usually choose the number with the variable (the letter) that looks like it will be easier to subtract. This leaves only 21 on the right side.
Next subtract 70 from both sides
Divide -13 by both sides
You should get the answer of r=7
Answer: x = pi/6 and x = pi/3.
Step-by-step explanation:
We have the function:
y = x + 2*cos(x)
It will have a horizontal tangent at the point where it's derivate is equal to zero.
Then first let's differentiate y.
y' = dy/dx = 1 - 2*sin(x).
Then we must find the value of x between 0 and 2*pi (or 0° and 360°)
y'(x) = 1 - 2*sin(x) = 0.
Let's solve that:
2*sin(x) = 1
sin(x) = 1/2.
We know that:
sin(30°) = 1/2.
and
Sin(120°) = 1/2
Then let's convert 30° into radians.
We know that:
pi = 180°.
Then:
pi/180° = 1.
30° = 30°*(pi/180°) = (30°/180°)*pi = (3/18)*pi = pi/6
120° = (120°/180°)*pi = (12/18)*pi = (1/3)*pi = pi/3.
Then the two values of x are: pi/6 and pi/3.
So Sahra is 3 times as old as her daugter. That means that the sum of their age is the daughters age times 4.
We can prove that by saying the daughters age is x. Sahra's age must be 3x. Their sum must be x+3x = 4x.
So to get the daughters age we divide the sum by 4, which is 8.
Answer - A
Explanation - 8 - 3 = 5 50 - 25 = 25
