Exponent & Logarithm Rules for Calculus

Calculus requires fluent translation between radical forms ($\sqrt{x}$) and exponential forms ($x^{1/2}$), as well as solving exponential and logarithmic equations.

Core Theorem
Key Properties: ax=1axa^{-x} = \frac{1}{a^x}, ap/q=apqa^{p/q} = \sqrt[q]{a^p}, and ln(ab)=ln(a)+ln(b)ln(ab) = ln(a) + ln(b). example

Practice Exercises


Example 01Easy
Rewrite using exponents and solve: 2x(4x)1/234x=02x(4-x)^{-1/2} - 3\sqrt{4-x} = 0.
NEED A HINT?
Convert 4x\sqrt{4-x} to (4x)1/2(4-x)^{1/2}. Factor out the term with the smallest exponent: (4x)1/2(4-x)^{-1/2}. example
SHOW DETAILED EXPLANATION

Step 1: Convert to Exponents

Rewrite the equation: 2x(4x)1/23(4x)1/2=02x(4-x)^{-1/2} - 3(4-x)^{1/2} = 0.

Step 2: Factor Out Common Term

Factor out (4x)1/2(4-x)^{-1/2}: (4x)1/2[2x3(4x)1]=0(4-x)^{-1/2} [ 2x - 3(4-x)^1 ] = 0. Note that subtracting exponents: 1/2(1/2)=11/2 - (-1/2) = 1.

Step 3: Solve Linear Part

Simplify inside the bracket: 2x12+3x=5x12=0x=12/52x - 12 + 3x = 5x - 12 = 0 \Rightarrow x = 12/5. (Check domain: 4x>04-x > 0).
Example 02Easy
Solve the logarithmic inequality: ln(x22x2)0ln(x^2 - 2x - 2) \le 0.
NEED A HINT?
Convert the log form to exponential form (e0=1e^0=1) AND ensure the argument of the log is positive (x22x2>0x^2-2x-2 > 0). example
SHOW DETAILED EXPLANATION

Step 1: Remove Log

x22x2e0x22x21x22x30x^2 - 2x - 2 \le e^0 \Rightarrow x^2 - 2x - 2 \le 1 \Rightarrow x^2 - 2x - 3 \le 0.

Step 2: Solve Outer Inequality

Factor (x3)(x+1)0(x-3)(x+1) \le 0. Solution: [1,3][-1, 3].

Step 3: Check Domain

You must also satisfy x22x2>0x^2 - 2x - 2 > 0. Find roots 1±31 \pm \sqrt{3}. The valid xx must be outside (13,1+sqrt3)(1-\sqrt{3}, 1+sqrt{3}). Intersect this with [1,3][-1, 3].
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