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KonstantinChe [14]

3 years ago

11

A golfer hits the golf ball. The quadratic function y = −16x^2 + 80x gives the time x seconds when the golf ball is at height 0

feet. How long does it take for the golf ball to return to the ground? HELP PLEASE!

1 answer:

svetlana [45]3 years ago

4 0

You need to calculate the two zeros of the function. The first zero is the "start", the second zero is the "end" of the trajectory.

Well...

0 = x(-16x+80)

First zero is x=0 (the start of trajectory)

Second zero:

-16x+80=0.... x=5! (The end of the trajectory!)

Good luck!
M.

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Step-by-step explanation:

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2 years ago

Jackson is starting an exercise program. The first day he will spend 30 minutes on the treadmill. He will increase his time on t

yulyashka [42]

Answer:

40 minutes.

Step-by-step explanation:

time spent on the thread mill as a function of d(day) = t(d)

= 30 +2(d-1) minutes

[where d represents day number]

(when d is 1 the time spent should be 30

so substitute d=1 and check it will be 30 only.

on first day he will spend 30 minutes so, I added 30 .

and on every additional day( these additional days are excluding first day), he will increase the time by 2 minutes.so, I added 2(d-1) to initial 30 minutes)

so, T(6), the minutes he will spend on the treadmill on day 6=

=30+2(6-1)

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=40 minutes

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3 years ago

What is 714 divided by 14?

ivanzaharov [21]

Answer:

51

Step-by-step explanation:

Hope this helps

3 0

3 years ago

Read 2 more answers

The sum of first three terms of a finite geometric series is -7/10 and their product is -1/125. [Hint: Use a/r, a, and ar to rep

Alchen [17]

Ooh, fun

geometric sequences can be represented as
$a_n=a(r)^{n-1}$
so the first 3 terms are
$a_1=a$
$a_2=a(r)$
$a_2=a(r)^2$

the sum is -7/10
$\frac{-7}{10}=a+ar+ar^2$
and their product is -1/125
$\frac{-1}{125}=(a)(ar)(ar^2)=a^3r^3=(ar)^3$

from the 2nd equation we can take the cube root of both sides to get
$\frac{-1}{5}=ar$
note that a=ar/r and ar²=(ar)r
so now rewrite 1st equation as
$\frac{-7}{10}=\frac{ar}{r}+ar+(ar)r$
subsituting -1/5 for ar
$\frac{-7}{10}=\frac{\frac{-1}{5}}{r}+\frac{-1}{5}+(\frac{-1}{5})r$
which simplifies to
$\frac{-7}{10}=\frac{-1}{5r}+\frac{-1}{5}+\frac{-r}{5}$
multiply both sides by 10r
-7r=-2-2r-2r²
add (2r²+2r+2) to both sides
2r²-5r+2=0
solve using quadratic formula
for $ax^2+bx+c=0$
$x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}$
so
for 2r²-5r+2=0
a=2
b=-5
c=2

$r=\frac{-(-5) \pm \sqrt{(-5)^2-4(2)(2)}}{2(2)}$
$r=\frac{5 \pm \sqrt{25-16}}{4}$
$r=\frac{5 \pm \sqrt{9}}{4}$
$r=\frac{5 \pm 3}{4}$
so
$r=\frac{5+3}{4}=\frac{8}{4}=2$ or $r=\frac{5-3}{4}=\frac{2}{4}=\frac{1}{2}$

use them to solve for the value of a
$\frac{-1}{5}=ar$
$\frac{-1}{5r}=a$
try for r=2 and 1/2
$a=\frac{-1}{10}$ or $a=\frac{-2}{5}$

test each
for a=-1/10 and r=2
a+ar+ar²= $\frac{-1}{10}+\frac{-2}{10}+\frac{-4}{10}=\frac{-7}{10}$
it works

for a=-2/5 and r=1/2
a+ar+ar²= $\frac{-2}{5}+\frac{-1}{5}+\frac{-1}{10}=\frac{-7}{10}$
it works

both have the same terms but one is simplified

the 3 numbers are $\frac{-2}{5}$ , $\frac{-1}{5}$ , and $\frac{-1}{10}$

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3 years ago

R=8 P=7 R+P= PLZ im stuck <br>

mihalych1998 [28]

Answer:

15

Step-by-step explanation:

The equation is just a plug in and solve. you have your given variables and all you have to do it plug them into the matching spot and solve

R=8 P=7

8+7=15

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