Hi ,
I read the following in somebody's handout..
how true is the exception mentioned..
If two lines are perpendicular to each other, the product of their slopes is -1. (m1 m2 = -1). (There is one
exception to this rule - when two lines are parallel to x and y axis respectively, then m1 m2 ≠-1, even if the
lines are perpendicular).
Geometry Doubt.
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- ceilidh.erickson
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The reason that the product of the slopes of lines parallel to the x and y axis will not be -1 is this: any line parallel to the x axis will have a slope of 0 (rise 0 / run... infinity), and any line parallel to the y axis will have a slope that is undefined (rise infinity / run 0). Any time you're dividing by 0, the fraction is undefined. If we multiply the slopes, 0 * undefined = undefined.
I've never seen this rule directly tested on a GMAT question, but of course it's possible that they might test it. (The GMAT very rarely asks about situations in which a ratio is undefined). Almost always, when the GMAT is testing perpendicular lines on a coordinate plane, they'll give slopes such as 1/3 and -3; these are negative reciprocals whose product is -1.
I've never seen this rule directly tested on a GMAT question, but of course it's possible that they might test it. (The GMAT very rarely asks about situations in which a ratio is undefined). Almost always, when the GMAT is testing perpendicular lines on a coordinate plane, they'll give slopes such as 1/3 and -3; these are negative reciprocals whose product is -1.
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
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amazing.. . thanks ceilidh.
I have a couple of questions.. got my gmat the coming thursday.
Do we need to remember the GMAT codes of 5 schools to which we want to send the scores or do we need to select the names from the drop down ?
Say, I want to do my mba 2 years from now.. So after 2 years when I apply, do I need to send the scores again?
Are we given limited scratch papers or can we ask for as many as we need. .
I have a couple of questions.. got my gmat the coming thursday.
Do we need to remember the GMAT codes of 5 schools to which we want to send the scores or do we need to select the names from the drop down ?
Say, I want to do my mba 2 years from now.. So after 2 years when I apply, do I need to send the scores again?
Are we given limited scratch papers or can we ask for as many as we need. .
Regards,
Sach
Sach
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- ceilidh.erickson
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No, you won't need to memorize the codes of the schools you want. There will be a drop-down menu.
You won't need to resend the scores - once you've sent them, the schools will keep them for up to 5 years (after which time the GMAT scores expire).
You will be given one pad of laminated scrap paper. If you run out, they'll bring a new one and take away the old one. I'd recommend getting a fresh pad during each break so you don't run out.
Good luck!
You won't need to resend the scores - once you've sent them, the schools will keep them for up to 5 years (after which time the GMAT scores expire).
You will be given one pad of laminated scrap paper. If you run out, they'll bring a new one and take away the old one. I'd recommend getting a fresh pad during each break so you don't run out.
Good luck!
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
EdM in Mind, Brain, and Education
Harvard Graduate School of Education