3: m= 2, -3
4: x= -1, 5/2
5: x= -1, -3
6: x= 5/2, -4
Answer:
Step-by-step explanation:
f(x) = 2x² + 14x - 4
= 2(x² + 7x) - 4
= 2(x² +7x + 3.5²) - 2(3.5²) - 4
= 2(x+3.5)² - 28.5
vertex (3.5, -28.5) = (7/2, -57/2)
The vertical intercept is the y-intercept, i.e., f(0) = -4.
The x-intercepts are the values of x for which y=0.
2x² + 14x - 4 = 0
x = [-14±√(14²-4(2)(-4))]/[2(2)] = [-7±√57]/2 ≅ -7.27, 0.27
You have to make a cos graph that starts its minimum and of -2, has an amplitude of 10, a period of 10 and a maximum of 18.
I decided to use a cos graph since cos graphs start at their minimum or maximum unlike a sine graph that starts halfway between the minimum and maximum. You also know the amplitude has to be 10 since 18+2=20 and 20/2=10. We were also told that the water wheel completels a rotation every 10 minutes which means the period is 10 minutes.
lets start of with a regular cos(x) graph. This starts on its maximum instead of minimum so we have to multiply it by -1 to get -cos(x) which does start on its minimum.
-cos(x) has an amplitude of 1 instead of 10, to fix that we multiply it by 10 to get -10cos(x) which has an amplitude of 10.
-10cos(x) has a period of 2π instead of 10, to fix this we multiply the x by 2π/10 to get -10cos((π/5)x) which now has a period of 10.
-10cos((π/5)x) has a minimum of -10 and maximum of 10 instead of a minimum of -2 and maximum of 18, to fix this we add 8 to -10cos((π/5)x) to get -10cos((π/5)x)+8 which does have a minimum of -2 and maximum of 18.
Therefore the answer is y=-10cos((π/5)x)+8. x being time in minutes and and y being the height in feet.
I hope this helps. Let me know if anything is unclear.
Z - 7 = 8
subtract 7 from both sides
z = 15
hope this helped!
It’s either C or B but I’m not sure
