SOLUTION: The angle of elevation from the top of a house to a jet flying 2 miles above the house is x radians. If d represents the horizontal distance, in miles, of the jet from the house, e

Algebra.Com
Question 352684: The angle of elevation from the top of a house to a jet flying 2 miles above the house is x radians. If d represents the horizontal distance, in miles, of the jet from the house, express d in terms of a trigonometric function of x. Then graph the function for 0 < x < Pi.
Answer by jsmallt9(3758)   (Show Source): You can put this solution on YOUR website!
It will probably help to have a drawing/diagram of the problem. Start with a point which we will name A. From A draw a horizontal line segment (the length of the segment is not important). At the end of this segment we will name the point B. From B draw a vertical line segment (again, the length of the segment is not important). At the end of this segment we will name the point C. Then draw a segment connecting points A and C. Write an "x" inside the angle formed at point A, write a "d" below segment AB and halfway between A and B and write a "2" next to segment BC and halfway between B and C.

We should now have a right triangle with the right angle at B (because horizontal and vertical are perpendicular). At A we have an angle of x radians. Segment BC has a length of 2 because the jet is 2 miles up. The distance we are interested in is "d", the horizontal distance.

To come up with a trigonometric equation for "d" we have to know the ratios represented by the various trig functions. Then we have to select the right one for this problem.

Looking at the diagram we should be able to tell that from the point of view of the ange at A, segment BC is the "opposite" side and that segment AB is the adjacent side. So we need a ratio involving opposite and adjacent sides. If we know the trig functions and their ratios we know that both tan (tangent) and cot (cotangent) are ratios of opposite and adjacent.

For reasons you will see shortly, I am going to pick the function which has the adjacent side in the numerator of the ratio. This would be cot. Writing an equation which connects tan to these particular opposite and adjacent sides we get:

To solve for d, all we have to do is multiply by 2! (This is why I chose cot. With d in the numerator it is much easier to solve for.)

The full graph of this looks like:

(I'll leave it up to you to truncate this graph to the interval of (0, ).

RELATED QUESTIONS

The angle of elevation from the top of a house to a jet flying 2 miles above the house is (answered by scianci)
A man is in a tree house 12 feet above the ground. He is looking at the top of another... (answered by Boreal)
A ladder leans against the side of a house. The angle of the elevation of the ladder is... (answered by user_dude2008,stanbon)
A ladder leans against the side of a house. The angle of elevation of the ladder is 67*... (answered by Alan3354)
1. Solve right triangle, ABC, giving the following information: Angle A=60 degrees,... (answered by mananth,jsmallt9)
A Building AB, is observed across a street from the window of a house 7 metres above the... (answered by drj)
Dan and Karen who live 10 miles apart meet at a cafe that is directly north of Dan's... (answered by solver91311)
Can someone help me with this trigonometry word problem? here goes: A helicopter... (answered by Theo)
From the top of a hill, the angle of depression to a house is measured to be 20o. If... (answered by ikleyn)