A line passes through and is perpendicular to the line . What is the -intercept of this line?
Answer and explanation
Correct answer: A.
- Step 1: Rewrite as , so its slope is .
- Step 2: A perpendicular slope is . Use point-slope form: .
- Step 3: Then , so the -intercept is .
Answer
.
Why not the others: uses the parallel slope with the wrong orientation; and are sign errors when adding and .
Practise more Lines and slope.
Free questions with an explanation for every one, and full timed ACT mock tests.