Question

Pre-calculus: At a certain time of day, a 15-meter mast casts a 20 meter shadow. What is the angle of elevation of the sun?

Answer 1

use the trig ratio to find x \[\rm sin \rm \theta = \frac{ opposite }{ hypotenuse }~~~~ \cos \theta = \frac{ adjacent }{ hypotenuse } ~~\tan \theta = \frac{ opposite }{ adjacent }\]

Answer 2

@Nnesha So I'm doing tan because I know that the opposite is 15, and the adjacent is 20? And that's my answer? 15/20?

Answer 3

yes right then use the calculator to find the exact value

Answer 4

I got .75, is that correct? @Nnesha

Answer 5

remember you should inverse tan \[\huge\rm tan( x) =\frac{ 15 }{ 20 }\]
\[x= \tan^{-1} \frac{ 15 }{ 20 }\]

Answer 6

find*

Answer 7

@Nnesha So the cotangent....? Sorry I just started pre-calc last week so I'm not sure how to do that.

Answer 8

tan and cot are `reciprocal` not inverse
use the calculator to find inverse tan

Answer 9

@Nnesha So tan(15/20) in the calculator?

Answer 10

not tan inverse tan
which calculator are u using google or ti84 ?

Answer 11

@Nnesha Oh I figured it out! The final answer is 36.9. Do you mind explaining why I have to find the inverse?

Answer 12

yes that's right
tan and invs are opposite
like when you have to find side then you should apply tan
and when you have to find `an angle ` then you should use invs tan

Answer 13

i found this from mathisfun website
http://prntscr.com/8e6m50

Answer 14

https://www.mathsisfun.com/algebra/trig-inverse-sin-cos-tan.html

Answer 15

@Nnesha Thank you SO much. Your help was amazing!

Answer 16

np glad it helped goood work btw! keep it up!