LEARN · EXPLAIN · REVISE

P is on the ellipse and PF1=t. Find PF2.

Read the idea, work independently, then explain what changed.

TOPIC 01

Conic sections: mixed review

A mixed assessment: identify the method, justify it and revise your reasoning.

Use one hint at a time. A correction explains what changed, not just the final answer.

01 / Standard#Your turn

a=28,\quad PF_1=26

For a horizontal major axis a>b>0; the larger denominator specifies the major axis.

Skills and prerequisite lessons

Working and explanation

BUILD THE REASONING

Hint 1

Translate the geometric condition into a coordinate equation.

Hint 2

Use this intermediate relation.

PF_1+PF_2=2a

Worked solution

The requested value is 30.

Checks and common pitfalls: The distance-sum definition avoids solving coordinates.

Think first. Reveal a hint when the class is ready.

Teacher preparation and assessment