The output for f(x) =x^2 - 1 when the input is x =4; that is, find f(4).

15

Step-by-step explanation:

4^2 - 1

16 - 1 = 15

f(4) = 15

y = -5/4 x + 2

Step-by-step explanation:

the slope of line segment : (1+7) /(9+1) = 8/10

= 4/5

the mid point of line segment :

x = (-1+9)/2= 4

y= (-7+1)/2 = -3

the coordinate : (4, -3)

the slope of line perpendicular to line segment

= -1 ÷ 4/5 = -5/4

so the equation :

y+3= -5/4 (x-4)

y+3= -5/4 x +5

y = -5/4 x + 2