Page 30 - Calc for the Clueless
P. 30
Rule 3
If y' = kz', then y = kz + C.
Rule 4
If y' = f' + g', then y = f + g + G.
Example 20—
Example 21—
Example 22—
2
If y' = 3x + 4x and y = 2 when x = 3, findy y.
Now x = 3, y = 2 to find G.
Rule 5
n
If y' = u du/dx with , then .
Note
Put u = x in rule 5 and you will have rule 2. We will discover that when N = -1, the antiderivative is a
logarithm.
Example 23—
99
Find y if y' = x(x + 1) .
2
We could multiply this out. On the grounds of sanity, we reject this technique.
Let u = (x + 1). du/dx = 2x.
2