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Find the tangent at the given point.

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

TOPIC 01

Equations of lines and circles: mixed review

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

What you will be able to explain

  • Connect the chapter skills without relying on the order of the exercises.

Try it. Leave your reasoning visible.

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

01 / Transfer#Your turn

Find the tangent at the given point.

x2+y2=28900,P=(102,136)x^2+y^2=28900, P=(102,136)
  • Compare center distance with r1+r2 and |r1−r2|; equal centers require separate treatment.
Skills and prerequisite lessons

Working and explanation

BUILD THE REASONING

Hint 1
Translate the geometric condition into a coordinate equation.
Hint 2
The radius is normal to the tangent.
Worked solution
  1. Translate the geometric condition into a coordinate equation.

  2. Apply the stated relation and retain its conditions.

    3(x−102)+4(y−136)=03(x-102)+4(y-136)=0
  3. Apply the stated relation and retain its conditions.

    3x+4y=8503x+4y=850
  4. The point is on the circle and fixes the tangent constant.

The requested relation or conclusion is shown below.

3x+4y=8503x+4y=850

Checks and common pitfalls: The point is on the circle and fixes the tangent constant.

Reasoning checklist · self / teacher assessment
  • State a valid definition or model and its assumptions.
  • Show the intermediate mathematical relations, not only the final claim.
  • Check exclusions, units or the interpretation of the result.

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

Focus on one question

Teacher preparation and assessment

Question sequence

  • Ask students to name the relevant condition before calculating.

Board plan

  • Compare valid methods and annotate their conditions.

Anticipated thinking

  • A correct final value may still hide a missing assumption.

Assessment checklist

  • Check the method, conditions, reasoning and interpretation separately.

No sign-in. Work stays in this browser. Export before clearing browser data. Written reasoning is assessed with a checklist.

Curriculum and source notes ↗