One and three tenths decreased by 4

The students in Mr. Wilson's Physics class are making golf ball catapults. The

Mnenie [13.5K]

Answer:

Part a) About 48.6 feet

Part b) About 8.3 feet

Part c) The domain is $0 \leq x \leq 48.6\ ft$ and the range is $0 \leq y \leq 8.3\ ft$

Step-by-step explanation:

we have

$y=-0.014x^{2} +0.68x$

This is a vertical parabola open downward (the leading coefficient is negative)

The vertex represent a maximum

where

x is the ball's distance from the catapult in feet

y is the flight of the balls in feet

Part a) How far did the ball fly?

Find the x-intercepts or the roots of the quadratic equation

Remember that

The x-intercept is the value of x when the value of y is equal to zero

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$-0.014x^{2} +0.68x=0$

so

$a=-0.014\\b=0.68\\c=0$

substitute in the formula

$x=\frac{-0.68(+/-)\sqrt{0.68^{2}-4(-0.014)(0)}} {2(-0.014)}$

$x=\frac{-0.68(+/-)0.68} {(-0.028)}$

$x=\frac{-0.68(+)0.68} {(-0.028)}=0$

$x=\frac{-0.68(-)0.68} {(-0.028)}=48.6\ ft$

therefore

The ball flew about 48.6 feet

Part b) How high above the ground did the ball fly?

Find the maximum (vertex)

$y=-0.014x^{2} +0.68x$

Find out the derivative and equate to zero

$0=-0.028x +0.68$

Solve for x

$0.028x=0.68$

$x=24.3$

Alternative method

To determine the x-coordinate of the vertex, find out the midpoint between the x-intercepts

$x=(0+48.6)/2=24.3\ ft$

To determine the y-coordinate of the vertex substitute the value of x in the quadratic equation and solve for y

$y=-0.014(24.3)^{2} +0.68(24.3)$

$y=8.3\ ft$

the vertex is the point (24.3,8.3)

therefore

The ball flew above the ground about 8.3 feet

Part c) What is a reasonable domain and range for this function?

we know that

A reasonable domain is the distance between the two x-intercepts

so

$0 \leq x \leq 48.6\ ft$

All real numbers greater than or equal to 0 feet and less than or equal to 48.6 feet

A reasonable range is all real numbers greater than or equal to zero and less than or equal to the y-coordinate of the vertex

so

we have the interval -----> [0,8.3]

$0 \leq y \leq 8.3\ ft$

All real numbers greater than or equal to 0 feet and less than or equal to 8.3 feet

8 0

3 years ago

A recipe called for 5/9 cup of chopped lettuce and 5/6 cup of diced lettuce. In total, how many cups of lettuce did the recipe c

77julia77 [94]

Answer:

1 7/18

Step-by-step explanation:

5/9 + 5/6 write all numerators above the least common denominator which is 18.

10+15/18 then you add the numerators which will make it 25/18 which alternative form will be 1 7/18, or in decimal 1.38

3 0

3 years ago

Help meee will give brainly! Find the domain of the function f(x)=5x−9 . DONT SAY I DONT KNOW

Agata [3.3K]

Answer and Step-by-step explanation:

$\frac{5}{x-9}$

The domain is all real numbers except 9 (positive)

This is because we can't have 0 in the denominator, and when x equals 9, then the denominator is 0. Anything divided by 0 is undefined, which is why 9 (in this equation) is not included.

#teamtrees #WAP (Water And Plant)

7 0

3 years ago

Please help i will give you points

SpyIntel [72]

Answer:

done

Step-by-step explanation:

I have installed it

6 0

3 years ago

Read 2 more answers

What is the y-intercept of this quadratic?

MAVERICK [17]

Answer:

(0,8)

Step-by-step explanation:

The line crosses the y axis at (0,8)

8 0

3 years ago