Answer:
72
Step-by-step explanation:
Well to make life easier just simplify the fraction
80/100 could be simplified to 4/5
4/5*90 is 72
Answer:
a) 13 m/s
b) (15 + h) m/s
c) 15 m/s
Step-by-step explanation:
if the location is
y=x²+3*x
then the average velocity from 3 to 7 is
Δy/Δx=[y(7)-y(3)]/(7-3)=[7²+3*7- (3²+3*3)]/4= 13 m/s
then the average velocity from x=6 to to x=6+h
Δy/Δx=[y(6+h)-y(6)]/(6+h-6)=[(6+h)²+3*(6+h)- (6²+3*6)]/h= (2*6*h+3*h+h²)/h=2*6+3= (15 + h) m/s
the instantaneous velocity can be found taking the limit of Δy/Δx when h→0. Then
when h→0 , limit Δy/Δx= (15 + h) m/s = 15 m/s
then v= 15 m/s
also can be found taking the derivative of y in x=6
v=dy/dx=2*x+3
for x=6
v=dy/dx=2*6+3 = 12+3=15 m/s
