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

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

zepdrix
 one year 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
 one year ago
Best ResponseYou've already chosen the best response.0oh i had put a 4/5

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

zepdrix
 one year 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
 one year ago
Best ResponseYou've already chosen the best response.04/5 correct? that would be the reciprocal

zepdrix
 one year 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
 one year 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
 one year 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
 one year ago
Best ResponseYou've already chosen the best response.0i think im messing up so where

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

zepdrix
 one year 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
 one year ago
Best ResponseYou've already chosen the best response.0i was doing it wrong

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

zepdrix
 one year 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
 one year 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
 one year ago
Best ResponseYou've already chosen the best response.0so the answer is y=5/4x+3
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