Make r the subject of the formula A= pi r (l+r)
A = πr(l+r) = πr^2 + πrl
πr^2 + πlr - A = 0
r = (-πl ±√((πl)^2 - 4πA))/(2π)
Who would want half the area of a cylinder?
To make r the subject of the formula A = πr(l + r), we need to isolate r.
Step 1: Distribute the πr to the terms inside the parentheses.
A = πrl + πr²
Step 2: Rearrange the equation to isolate the term with r.
πr² + πrl = A
Step 3: Move the πrl term to the other side of the equation.
πr² = A - πrl
Step 4: Divide both sides of the equation by π.
r² = (A - πrl) / π
Step 5: Take the square root of both sides to solve for r.
r = √((A - πrl) / π)
So, r is the subject of the formula A = πr(l + r), and it can be expressed as r = √((A - πrl) / π).
To make "r" the subject of the formula A = πr(l + r), we need to isolate "r" on one side of the equation. Here's how we can do it step by step:
1. Distribute πr to both terms inside the parentheses:
A = πrl + πr²
2. Move πrl to the right side of the equation by subtracting it from both sides:
A - πrl = πr²
3. Right side of the equation now becomes πr². To make it easier to work with, divide both sides of the equation by π:
(A - πrl) / π = r²
4. Take the square root of both sides of the equation:
√((A - πrl) / π) = r
So, the subject "r" can be expressed as:
r = √((A - πrl) / π)
Hence, you can use the formula above to solve for "r" when you know the values of A, l, and r.