Parabola
General
Grade 11
Question:
If the lines (y – b) = m<span class="math-inline">1</span>(x + a) and (y – b) = m<span class="math-inline">2</span>(x + a) are the tangents to the parabola y<span class="math-inline">^2</span> = 4ax, then
m<span class="math-inline">1</span> m<span class="math-inline">2</span> = 0
m<span class="math-inline">1</span> m<span class="math-inline">2</span> = 1
m<span class="math-inline">1</span> m<span class="math-inline">2</span> = –1
m<span class="math-inline">1</span> + m<span class="math-inline">2</span> = 1
Step-by-Step Solution
Key Concept: General
x² + y² - by(tan(φ/2) + cot(φ/2)) - a² + b² = 0
Correct Answer: x² + y² - by(tan(φ/2) + cot(φ/2)) - a² + b² = 0