Answer:
(B) π/12 + π/6 k
Step-by-step explanation:
Points of inflection are where f"(x) = 0 and changes signs.
f(x) = cos²(3x)
f(x) = (cos(3x))²
f'(x) = 2 (cos(3x))¹ × -sin(3x) × 3
f'(x) = -6 sin(3x) cos(3x)
Using double angle formula:
f'(x) = -3 sin(6x)
f"(x) = -3 cos(6x) × 6
f"(x) = -18 cos(6x)
0 = -18 cos(6x)
0 = cos(6x)
6x = π/2 + 2πk or 6x = 3π/2 + 2πk
We can simplify this to:
6x = π/2 + πk
x = π/12 + π/6 k
Answer:
x = -6, y = -2
Step-by-step explanation:
2x-7y = 2
3x + y = -20
We need to cancel out either x or y to solve the equation. I'll cancel out x first
3(2x-7y = 2)
-2(3x+y=-20)
___________
6x-21y = 6
-6x -2y = 40
____________
-23y = 46
y = -2
Plug the value for y in one of the 2 equations to solve for x
2x -7(-2) = 2
2x+14=2
2x = -12
x=-6
Answer:
10/8
Step-by-step explanation:
What you should do is awfully simple. Multiply 2 by 5 and put the product over 8.
(2 * 5)/8
10/8
The problem does say to leave my answer as an improper fraction, so 10/8 is the final answer.
Forty-one thousand, and seven
