Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
Evaluate the indefinite integral. ∫2(31)xdx
A
−3xln32+C
B
−42xx+1+C
C
−ln32x+C
D
−3xln42xx+1+C
Verified step by step guidance
1
Step 1: Recognize that the integral involves an exponential function of the form \( \left( \frac{1}{3} \right)^x \). Rewrite this as \( 2 \cdot \left( \frac{1}{3} \right)^x \), which can also be expressed as \( 2 \cdot 3^{-x} \).
Step 2: Recall the general formula for integrating exponential functions: \( \int a^{u} \cdot u' \, dx = \frac{a^{u}}{\ln(a)} + C \), where \( a > 0 \) and \( a \neq 1 \). In this case, \( a = 3 \) and \( u = -x \).
Step 3: Differentiate \( u = -x \) to find \( u' = -1 \). This means we need to account for the negative sign when integrating.
Step 4: Apply the formula for the integral. The integral becomes \( \int 2 \cdot 3^{-x} \, dx = 2 \cdot \frac{3^{-x}}{-\ln(3)} + C \). Simplify the expression to \( -\frac{2}{3^x \ln(3)} + C \).
Step 5: Combine the constant of integration \( C \) to complete the solution. The final expression is \( -\frac{2}{3^x \ln(3)} + C \).