You multiply a number by 3 subtract 6 then add 2 the results is 20
what's the number ?
Let the number = x
multiply a number by 3
so, it becomes 3x
subtract 6 , so, 3x - 6
then add 2
so, 3x - 6 + 2
The result will be 20
So,
3x - 6 + 2 = 20
solve for x
3x - 4 = 20
Add 4 to both sides
3x - 4 + 4 = 20 + 4
3x = 24
Divide both sides by 3
3x/3 = 24/3
So,
x = 8
Split up the integration interval into 4 subintervals:
![\left[0,\dfrac\pi8\right],\left[\dfrac\pi8,\dfrac\pi4\right],\left[\dfrac\pi4,\dfrac{3\pi}8\right],\left[\dfrac{3\pi}8,\dfrac\pi2\right]](https://tex.z-dn.net/?f=%5Cleft%5B0%2C%5Cdfrac%5Cpi8%5Cright%5D%2C%5Cleft%5B%5Cdfrac%5Cpi8%2C%5Cdfrac%5Cpi4%5Cright%5D%2C%5Cleft%5B%5Cdfrac%5Cpi4%2C%5Cdfrac%7B3%5Cpi%7D8%5Cright%5D%2C%5Cleft%5B%5Cdfrac%7B3%5Cpi%7D8%2C%5Cdfrac%5Cpi2%5Cright%5D)
The left and right endpoints of the
-th subinterval, respectively, are


for
, and the respective midpoints are

We approximate the (signed) area under the curve over each subinterval by

so that

We approximate the area for each subinterval by

so that

We first interpolate the integrand over each subinterval by a quadratic polynomial
, where

so that

It so happens that the integral of
reduces nicely to the form you're probably more familiar with,

Then the integral is approximately

Compare these to the actual value of the integral, 3. I've included plots of the approximations below.
Answer:
.375
Step-by-step explanation:
divide 3 by 8
Since he gained 4.5 lbs but he lost 4 + 3.5 + 2 = 9.5 lbs, in total, he lost 5 lbs.
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