Ying is a professional deep water free diver. His altitude (in meters relative to sea level), xxx seconds after diving, is modeled by:
D(x)=\dfrac{1}{36}(x-60)^2-100D(x)=
36
1
​
(x−60)
2
−100D, left parenthesis, x, right parenthesis, equals, start fraction, 1, divided by, 36, end fraction, left parenthesis, x, minus, 60, right parenthesis, squared, minus, 100
What is the lowest altitude Ying will reach?

-100 meters is the answer

The lowest point is -100 meters, or 100 meters down

Step-by-step explanation:

D(x)=1/36(x-60)^2-100

This equation is in vertex form

y = a(x-h)^2 +k  where (h,k) is the vertex

Since a is positive, the parabola opens up

The vertex is the minimum, which means it will be the lowest point

The vertex is (60,-100)

The lowest point is -100 meters, or 100 meters down

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)