Find the area under the curve y = 4 which is bounded from x = -1 to x = 2.

Question

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Find the area under the curve y = 4 which is bounded from x = -1 to x = 2.

a.4

b.12

c.8

d.21/32

Answer 1

b. 12

area under y=4, between x=-1 and x=2 is a rectangle 3 by 4, 3x4 = 12

height = 4, base = 2--1 = 2+1= 3

that's the geometry method, just graph the lines y=4, the x axis and two vertical lines x=-1, x=2

those 4 lines surround a rectangle 3 by 4

or use calculus

find the integral of 4dx, evaluated from -1 to 2

the integral = 4x

evaluated at -1 to 2

is 4(2) - (4(-1) = 8 +4 = 12