**Miscellaneous Exercise on Chapter 9** 1. Find the values of kk for which the line (k−3)x−(4−k2)y+k2−7k+6=0(k-3)x - (4-k^2)y + k^2 - 7k + 6 = 0 is (a) Parallel to the xx -axis, (b) Parallel to the yy -axis, (c) Passing through the origin. 2. Find the equations of the lines, which cut-off intercepts on the axes whose sum and product are 11 and −6-6, respectively.

Answer: (a) k=3k = 3, (b) k=±2k = \pm 2, (c) k=1k = 1 or k=6k = 6

Step-by-step solution

Step 1: Analyze the general linear equation

Comparing the given equation with the general equation of a line Ax+By+C=0Ax + By + C = 0, we identify A=k−3A = k - 3, B=−(4−k2)=k2−4B = -(4 - k^2) = k^2 - 4, and C=k2−7k+6C = k^2 - 7k + 6.

Step 2: Condition for line parallel to the x-axis

A line Ax+By+C=0Ax + By + C = 0 is parallel to the xx -axis if the coefficient of xx is zero and the coefficient of yy is non-zero. Here, A=k−3=0A = k - 3 = 0, which gives k=3k = 3. For k=3k = 3, the coefficient of yy is −(4−32)=5≠0-(4 - 3^2) = 5 \neq 0, so the line is parallel to the xx -axis.

Step 3: Condition for line parallel to the y-axis

A line is parallel to the yy -axis if the coefficient of yy is zero and the coefficient of xx is non-zero. Setting 4−k2=04 - k^2 = 0 yields k2=4k^2 = 4, so k=2k = 2 or k=−2k = -2. For both values, the coefficient of xx is k−3≠0k - 3 \neq 0, so the condition is satisfied.

Step 4: Condition for line passing through the origin

A line passes through the origin (0,0)(0, 0) if its constant term is zero, meaning C=0C = 0. Factorising k2−7k+6=0k^2 - 7k + 6 = 0 gives (k−1)(k−6)=0(k - 1)(k - 6) = 0, which yields k=1k = 1 or k=6k = 6. For both values, the coefficients AA and BB are not simultaneously zero.

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