Practicing Success
The point on the curve y = (x - 1)(x - 2) at which the tangent makes an angle of 135° with the positive direction of x-axis has coordinates |
(1, 0) (0, 1) (-1, 0) (0, -1) |
(1, 0) |
Let $\left(x_1, y_1\right)$ be the required point. Then, $\left(\frac{d y}{d x}\right)_{\left(x_1, y_1\right)}=\tan 135^{\circ}$ $\Rightarrow 2 x_1-3=-1$ $\left[∵ y=(x-1)(x-2) \Rightarrow \frac{d y}{d x}=2 x-3\right]$ $\Rightarrow x_1=1$ Since $\left(x_1, y_1\right)$ lies on $y=(x-1)(x-2)$ ∴ $y_1=\left(x_1,-1\right)\left(x_1-1\right)=(1-1)(1-2)=0$ Hence, (1, 0) is the required point. |