Straight Lines
Slope and Inclination
Grade 11
Question:
<p>Find the value of <span class="math">\(l\)</span> such that point <span class="math">\(D(2, 1)\)</span> lies on line <span class="math">\(AD\)</span> where <span class="math">\(A(4, l)\)</span> is given and the slope of <span class="math">\(AD\)</span> is 2.</p>
Step-by-Step Solution
Key Concept: Use the slope formula to relate the coordinates of two points and solve for the unknown parameter.
<p><strong>Solution:</strong></p><p>The slope of line <span class="math">\(AD\)</span> is given by:</p><p><span class="math">\(\text{Slope} = \frac{l - 1}{4 - 2} = \frac{l - 1}{2}\)</span></p><p>Given that the slope is 2:</p><p><span class="math">\(\frac{l - 1}{2} = 2\)</span></p><p><span class="math">\(l - 1 = 4\)</span></p><p><span class="math">\(l = 5\)</span></p>
Correct Answer: 5