A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 3 years ago
passing through (4,2) and perpendicular to x=5/4y2. Write in slope intercept form.
anonymous
 3 years ago
passing through (4,2) and perpendicular to x=5/4y2. Write in slope intercept form.

This Question is Closed

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1is the negative 2 also in the denominator? It's a little hard to read correctly without brackets.\[\large x=\frac{5}{4y2}\]

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1\[\large x=\frac{5}{4}y2\]Oh like this? :) That would make more sense lol

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0no it isn't. it's like the second one you just put up.

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1Let's first get our line into slopeintercept form, so we can accurately identify the slope. We want it in this form,\[\large y=mx+b\] \[\large x=\frac{5}{4}y2\]Start by adding 2 to each side,\[\large x+2=\frac{5}{4}y\]Multiply each side by 4/5,\[\large \frac{4}{5}(x+2)=\left(\frac{5}{4}y\right)\frac{4}{5}\]The fractions will cancel out on the right, giving us,\[\large y=\frac{4}{5}x+\frac{8}{5}\] So we've got our line in slopeintercept form, this will make it easier to work with. Understand those steps so far?

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0but yes other than that i get it so far

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1So it looks like our slope \(\large m\) is \(\large \dfrac{4}{5}\). Do you know what it means for a line to be `perpendicular`? It relates to the slope. :) Since the line we're trying to form is perpendicular to this line, it will have a slope that is a `negative reciprocal` of this slope. Do you understand what that means? c:

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.04/5 correct? that would be the reciprocal

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1Hmm I believe it's going to be, 5/4. Yes the negative looks good. But then we take the reciprocal (the flip) of our fraction.

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1So we're trying to form an equation for a line perpendicular to the given line. Let's call this new line something likeeeee \(\large y_p\). So we're trying to get an equation for this line, \(\large y_p=mx+b\). We've determined that the slope is, \(\large m=\dfrac{5}{4}\). Now we need to find the \(\large b\) value, the `yintercept`. To do so, we'll plug in the coordinate pair they gave us, that this line passes through.

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1So plug \(\large (4,2)\) into our equation \(\large y_p=\dfrac{5}{4}x+b\).

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0i think im messing up so where

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0for som reason im getting y=4/5x+6/5

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1So plugging in our point gives us,\[\large 2=\frac{5}{4}(4)+b\]The 4's will cancel out,\[\large 2=\frac{5}{\cancel4}(\cancel4)+b\]Giving us,\[\large 2=5+b\]Adding 5 to each side,\[\large b=3\] Did you do something different?

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0so y=4/5x+8/5 is correct?

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1This was the equation of the line we started with, \[\large y=\frac{4}{5}x+\frac{8}{5}\] They gave us a bunch of information to find a different line. And that was this line,\[\large y_p=mx+b\] We determined that the slope is \(\large m=\dfrac{5}{4}\). And that the yintercept is \(\large b=3\).

zepdrix
 3 years ago
Best ResponseYou've already chosen the best response.1The p doesn't mean anything, you don't need to put that if you don't want. It was just so we could tell it apart from our original y, which referred to a different line.

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0so the answer is y=5/4x+3
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.