Y = t*e^(-t/2)
y' = t' [e^(-t/2)] + t [e^(-t/2)]' = e^(-t/2) + t[e^(-t/2)][-1/2]=
y' = [e^(-t/2)] [1 - t/2] = (1/2)[e^(-t/2)] [2 - t] = - (1/2) [e^-t/2)] [t -2]
Answer:
D=24
Step-by-step explanation:
y inversely as x
x=k/y
By cross multiplication
k=xy
k=12*6
k=72
finding y
72=3y
y=24
Answer:
≈ 77 cm²
Step-by-step explanation:
The area of the shaded portion is calculated as
area of outer sector - area of inner sector
= (πR² - π r²) ×
( R is the outer radius, r is the inner radius )
= (π × 14² - π × 7² ) × 
= (196π - 49π ) ÷ 6
= 147π ÷ 6
≈ 77 cm² ( nearest whole number )
Answer:
B
Step-by-step explanation: