<u>Step-by-step explanation:</u>
Use the formula y = A cos (Bx - C) + D where
- A = amplitude
- Period = 2π/B
- Phase Shift = C/B
- D = vertical shift (aka midline)
Given: Max = 8, Min = 2, (1/2)Period = 20 → Period = 40
Amplitude (A) = (Max - Min)/2
= (8 - 2)/2
= 6/2
= 3
Midline (D) = (Max + Min)/2
= (8 + 2)/2
= 10/2
= 5
Period = 2π/B
→ B = 2π/Period
= 2π/40
= π/20
Notice that the Minimum touches the y-axis (not the Max) so there is no phase shift but there is a reflection → C-value = 0 & A-value is negative
Now, let's put it all together:
A = -3, B = π/20, C = 0, D = 5
The radius is 1.703......
First you must distribute the 2x to the numbers inside the parentheses
(2x * x) + (2x * -1) = 3
- 2x = 3
To make this a quadratic equation you can solve bring the 3 over to the left side of the equation by subtracting it to both sides
- 2x - 3 = 0
Use the quadratic equation to solve this (image of the quadratic equation is below)
Remember that quadratic functions are set up like so:
That means that in this equation...
a = 2
b = -2
c = -3
^^^Plug these numbers into the quadratic equation and solve...
Keep in mind that +/- is ±
^^^Exact answers
Approximations:
1.823
-0.823
Hope this helped!
~Just a girl in love with Shawn Mendes
Same, i need help with geometry too :(
