Hello, Sarah!
1) The arm of a boom crane is 12m long.
Because of the location of the construction site, the angle of inclination
of the boom of the crane has a minimum value of 30° and a maximum of 45°.
Find the vertical displacement of the end of the boom as
a) an exact value
b) an approximate value, to the nearest tenth of a metre. Code:
*
* |
12 * |
* | y1
* |
* 30° |
* - - - - - - - - * You're expected to the ratio of the sides of a 30-60 right triangle.
The side opposite the 30°-angle is always one-half the hypotenuse.
Hence: .
m.
Code:
*
* |
12 * |
* | y2
* |
* 45° |
* - - - - - * You should know that sides of a 45-45 right triangle are in the ratio: . 
Hence: . 
Therefore: . \;y_2 - y_1 \;=\;6\sqrt{2} - 6 \;=\;6(1-\sqrt{2})\;m )
. . . . . . . . \;y_2-y_1 \;=\;2.485281376 \;\approx\; 2.5\;m)
.