# Algebra Help Please?! What is the slope of a line perpendicular to the line y=4x+1?

What is the slope of a line perpendicular to the line y=4x+1

I have the answer. This is a practice question for my test tommorow. I just dont know how to figure out the answer. How would I solve this problem? Its very confusing for me. Thank you

I know the answer is -1/4 but how do I figure that out? This type of problem is going to be on my test

Thanks also does anyone know 8. What is the inverse function of f(x)=4x-1? I am horrible at functions!

### 12 Answers

- 1 decade agoBest Answer
Well you probably should have learned in class that two lines are perpendicular if the m's (from y = mx + b) are negative reciprocals of each other. Using that knowledge, we take the reciprocal of 4 and get 1/4 and then put a negative sign infront of it. The b (from y = mx +b) of the new equation can be anything and will still be perpendicular.

Hope that help. Good luck tomorrow.

- MoonRoseLv 71 decade ago
Slope-intercept form is y = mx + b, where m is the slope. Perpendicular lines have slopes that are opposite reciprocals of each other. Line y = 4x + 1 has a slope of 4, so a slope perpendicular to it is -1/4.

- HarukaLv 51 decade ago
A line perpendicular to another has the same slope, but the inverse, and negative. So in this problem, the slope would be -1/4.

- ?Lv 71 decade ago
the product of the slope of a line and its perpendicular is always =-1,

so the slope of a line perpendicular to y=4x+1 is equal to --1/4

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- Anonymous1 decade ago
y=mx+b where m is the slope. so the slope is 4/1. to graph it go to 1 on the y axis and mark it. then from there go up 4 and over one

- Anonymous1 decade ago
dont worry i can help you! 1 sec.... the slope of that line its 4 so a slope perpendicular would be the NEGATIVE RECIPROCAL, which is -1/4....good luck!

- ameenLv 43 years ago
-3 via fact perpendicular lines have a slope it fairly is the choice reciprocal. the choice is (situations -one million) and the reciprocal is one million over in spite of the unique slope is. one million over one million/3 is properly one million situations 3, it fairly is 3. so the choice reciprocal is -3