x→∞limxαβ⋅(loge(1+x))βsinx2⋅(logex)α⋅sinx21=0x→∞lim(loge(x+1))β⋅xαβ+2(logex)α=0x→∞lim(loge(x+1)logex)β⋅xαβ+2(logex)α−β=0x→∞limxαβ+2(logex)α−β=0 Put logex=tt→∞lim(et)αβ+2tα−β=0Asweknow\lim _{x \rightarrow \infty} \frac{x}{e^x}=0 \alpha \beta+2>0 \Rightarrow \alpha \beta>-2$