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Find the equation of the straight line passing through (1, 2) and perpendicular to the line x + y + 7 = 0. - Mathematics

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Question

Find the equation of the straight line passing through (1, 2) and perpendicular to the line x + y + 7 = 0.

Sum
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Solution

Let m be the slope of the line whose equation is to be found out which is perpendicular to the line x + y + 7 = 0.

The slope of the given line y = (– 1)x – 7 is – 1.

Therefore, using the condition of perpendicularity of lines

We have m × (– 1) = – 1 or m = 1 (Why?)

Hence, the required equation of the line is y – 1

= (1)(x – 2) or y – 1

= x – 2x – y – 1

= 0.

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Chapter 10: Straight Lines - Solved Examples [Page 169]

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NCERT Exemplar Mathematics [English] Class 11
Chapter 10 Straight Lines
Solved Examples | Q 4 | Page 169

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