Solve the following inequalities for x: $\frac{1}{x} < 1$ |
$(−∞,1)$ $(1,∞)$ $(−∞,0)∪(1,∞)$ $(0,1)$ |
$(−∞,0)∪(1,∞)$ |
The correct answer is Option (3) → $(−∞,0)∪(1,∞)$ Given $\frac{1}{x}< 1$. First, we note that $x≠ 0$. Since $x^2 > 0$ for all $x ∈ R, x ≠0,$ $\frac{1}{x}<1 ⇒ \frac{1}{x}.x^2 < x^2$ (multiplying by $x^2$) $⇒ x < x^2 ⇒ 0 < x^2-x$ $⇒ x(x-1)>0$ ...(1) Mark the numbers 0 and 1 on the real line. By the method of intervals, the inequality (1) is satisfied when $x > 1$ or $x < 0$. ∴ The solution set is $(−∞,0)∪(1,∞)$. |