Can someone please clearly and correctly work out Q19? Would appreciate it a lot! :)
1 answer:
I always start by moving the last term to the other side
To complete the square you take term 'b' , divide it by 2 then square it
We have to add 25 to what we have and what you do to one side you have to do to the other
Now we factor what is on the left side of the equation
The last step is to move our right side of the equation back over
You might be interested in
Check the picture.
let the length of a side of each of the squares removed be x.
The box formed will have dimensions: 80-2x, 50-2x, x(the height)
So the volume can be expressed as a function of x as follows:
f(x)=(80-2x)(50-2x)x=![[4000-160x-100x+4 x^{2} ]x=(4 x^{2}-260x+4000)x](https://tex.z-dn.net/?f=%5B4000-160x-100x%2B4%20x%5E%7B2%7D%20%5Dx%3D%284%20x%5E%7B2%7D-260x%2B4000%29x)
so
the solutions of f'(x)=0 gives the inflection points, so the candidates for maxima points,
solving the quadratic equation, either by a calculator, graphing software, or by other algebraic methods as the discriminant formula, we find the solutions
x=10 and x=33.333
plug in f(x) these values to see which greater:
cm cubed
which is negative because (50-66.666)<0
Answer: 18000 cm cubed
let the length of a side of each of the squares removed be x.
The box formed will have dimensions: 80-2x, 50-2x, x(the height)
So the volume can be expressed as a function of x as follows:
f(x)=(80-2x)(50-2x)x=
so
the solutions of f'(x)=0 gives the inflection points, so the candidates for maxima points,
solving the quadratic equation, either by a calculator, graphing software, or by other algebraic methods as the discriminant formula, we find the solutions
x=10 and x=33.333
plug in f(x) these values to see which greater:
Answer: 18000 cm cubed