An evergreen nursery usually sells a certain shrub after 7 years of growth and shaping. The growth rate during those 7 years is approximated by dh/dt = 1.3t + 2, where t is the time in years and h is the height in centimeters. The seedlings are 17 centimeters tall when planted (t = 0). (a) Find the height after t years. h(t) = (b) How tall are the shrubs when they are sold? cm

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Answer:

(a)[tex]h(t)=\frac{1.3t^2}{2} + 2t +17[/tex]

(b)62.85cm

Step-by-step explanation:

The growth rate of the shrub is given as:

[tex]\frac{dh}{dt} = 1.3t + 2[/tex]

Where t=time in years, h=height in centimeters

(a)First, we solve for the height h(t) by integrating.

[tex]\int \frac{dh}{dt} dt= \int (1.3t + 2)dt\\h(t)=\frac{1.3t^2}{2} + 2t +C, $ C a constant of Integration$\\$We sunstitute the initial value to find the value of C$\\$When t=0, h=17cm$\\17=C\\Therefore:\\h(t)=\frac{1.3t^2}{2} + 2t +17[/tex]

(b)The shrub are sold after 7 years of growth. Therefore, we determine the value of h(t) when t=7 years.

[tex]h(t)=\frac{1.3t^2}{2} + 2t +17\\h(7)=\frac{1.3*7^2}{2} + 2(7) +17\\=31.85+14+17\\h(7)=62.85cm[/tex]

The Shrubs are 62.85cm tall when they are sold.