Answer:
- increasing: (π/2, 3π/2)
- decreasing: [0, π/2) ∪ (3π/2, 2π]
- minimum: -16 at x=π/2
- maximum: 16 at x=3π/2
Step-by-step explanation:
If all you want are answers to the questions, a graphing calculator can provide them quickly and easily. (see attached)
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If you need an algebraic solution, you need to find the zeros of the derivative.
f'(x) = -16cos(x)sin(x) -16cos(x) = -16cos(x)(sin(x) +1)
The product is zero where the factors are zero, at x=π/2 and x=3π/2.
These are the turning points, where the function changes from decreasing to increasing and vice versa.
(sin(x)+1) is non-negative everywhere, so the sign of the derivative is the opposite of the sign of the cosine function. This tells us the function f(x) is increasing on the interval (π/2, 3π/2), and decreasing elsewhere (except where the derivative is zero).
The function local extrema will be where the derivative is zero, so at f(π/2) (minimum) and f(3π/2) (maximum). We already know that cos(x) is zero there, so the extremes match those of -16sin(x).
1 is A&B
2 is A
3 is C
Hope this helps.
Answer:$27
Step-by-step explanation:
cost price(cp)=$36
Percentage off=25
sale price=sp
Percentage off=(cp-sp)/cp x 100
25=(36-sp)/36 x 100
Cross multiplying we get
25x36=100(36-sp)
900=100(36-sp)
Divide both sides by 100 we get
900/100=100(36-sp)/100
9=36-sp
Collect like terms
sp=36-9
sp=27
Domain={-4,3} range={2,3}
Answer: Area = 6m²
Smaller number = 16
Hours = 9.6 h
Step-by-step explanation:
A rectangle is 5 meters longer than its width. If the length is shortened by 2 meters and width is increased by 1 meter, the area remains the same. Find the area of the rectangle.
1) w = x m 2) w = x + 1 m
l = x + 5 m l = x + 5 - 2 = x + 3 m
A₁ = A₂
A = w*l
A₁ = x(x+5) = x² + 5x
A₂ = (x+1)(x+2) = x² + x + 2x + 2 = x² + 3x + 2
A₁ = A₂
x² + 5x = x² + 3x + 2
5x - 3x = 2
2x = 2
x = 1
A₁ = x(x+5) = 1.6 = 6 m²
The ratio of two numbers is 2:5. If the larger number is 40, what is the smaller number.
<u> 2 </u> = <u> x </u>
5 40
5x = 80
x = 80/5 = 16
Sixteen construction workers can finish cementing a floor of a building in 3 hours. On a certain day, only 5 construction workers are available for the job. How long will it take the 5 construction workers to do the cementing job?
workers hours
16 3
5 x
↑ ↓ inversely proportional
<u> 5 </u> = <u> 3 </u>
16 x
5x = 16*3
5x = 48
x = 48/5
x = 9.6 h