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krissywatts
 2 years ago
passing through (4,2) and perpendicular to x=5/4y2. Write in slope intercept form.
krissywatts
 2 years ago
passing through (4,2) and perpendicular to x=5/4y2. Write in slope intercept form.

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zepdrix
 2 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
 2 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

krissywatts
 2 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
 2 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?

krissywatts
 2 years ago
Best ResponseYou've already chosen the best response.0oh i had put a 4/5

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

zepdrix
 2 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:

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

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

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

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

zepdrix
 2 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?

krissywatts
 2 years ago
Best ResponseYou've already chosen the best response.0i was doing it wrong

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

zepdrix
 2 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
 2 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.

krissywatts
 2 years ago
Best ResponseYou've already chosen the best response.0so the answer is y=5/4x+3
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