If the area above x-axis, bounded by the curves $y = 3^{βx}, x = 0$ and $x = 3$ is $\frac{26}{\log_e3}$ then the value $β$ is: |
$β=2$ $β=1$ $β=-1$ $β=\frac{1}{2}$ |
$β=1$ |
The correct answer is Option (2) → $β=1$ Given$\text{Area}=\int_{0}^{3}3^{\beta x}\,dx=\frac{26}{\ln 3}$ $\int_{0}^{3}3^{\beta x}\,dx=\int_{0}^{3}e^{\beta x\ln 3}\,dx=\frac{1}{\beta\ln 3}\big(3^{3\beta}-1\big)$ $\frac{3^{3\beta}-1}{\beta\ln 3}=\frac{26}{\ln 3}$ $\frac{3^{3\beta}-1}{\beta}=26$ $3^{3\beta}-1=26\beta$ Check $\beta=1$: $3^{3}-1=27-1=26=26\cdot 1$ Answer$\beta=1$ |