Geomtry help?
39. A map of a city and suburbs shows an airport located at A(25, 11). An ambulance is on a straight expressway headed from the airport to Grant Hospital at G(1, 1). The ambulance gets a flat tire at the midpoint M of . As a result, the ambulance crew calls for helicopter assistance. a. What are the coordinates of point M? b. How far does the helicopter have to fly to get from M to G? Assume all coordinates are in miles.
Ok. do you know the midpoint and the distance formula?
no?
http://www.purplemath.com/modules/midpoint.htm http://www.purplemath.com/modules/distform.htm
That website gives good explanations of both. You should go and check those out and then come back here so I can help if you still need it.
ok can we work on it?
Sure. First lets do the first part. Can you see which of the two formulas we would need there?
midpoint
Right! So I'll set that one up.
\[\frac{ 25+1 }{2 },\frac{ 11+1 }{ 2 }\]
oh got it, whats next?
Well now we have the point where the ambulance stopped. which after simplification is the point (13,6), and we have the point (1,1) and we need to know how far apart they are.
So we use the distance formula. I'll go ahead and set that one up.
\[\sqrt{(13-1)^{2}+(6-1)^{2}}\]
do I put that into my cal?
Yup.
even square root?
is that 13 sub 1 or is it neg?
Yup all of it. You could simplify first if you wanted to though.
so the (13-1)^2 = 144 and the (6-1)^2 =25
ok got it! than do I add 144 + 25?
Yup. Then you take the square root of that and thats the distance from point M to G.
so I do sqare root 169 in my cal?
Yes.
I got 13
I got the same thing. Looks like thats your answer!
for A and B?
Well we found a earlier remember? Its asking for the coordinates of the midpoint in part a. We found that right?
ohh, wait what was a afgain the answer?
Scroll up and take a look. What was the final answer after we used the midpoint formula?
was it the sqare root of 13-1?
No. The midpoint formula doesn't have any square roots.
25+1 / 2 that one right?
Right. But thats only the x component of the answer.
what do u mean?
When we use the midpoint formula we are finding a point in the coordinate plane. Points are always ordered with the x component first and the y second, like this (x,y). So the first part of our answer Is the x component of the point and the second part is the y component.
So, 25+1/2=x and 11+1/2=y
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