math question

[Skateguitar]

---

Members do not see this ad.

a 20 foot long ladder is leaning against a vertical wall such that the base of the ladder is 13 feet from the wall. what angle does the ladder make with the ground?

a. arcsin(13/20)
b. arccos(20/13)
c. arctan(13/20)
d. arctan(20/13)
e. arccos(13/20)

answer is e. but i am completely lost to go about answering this question with the arcs. if it was only cos,sin, tan then I could solve it but i am lost here.

 

[silveryhair]

OKay, so the Hypotenuse is 20, and the bottom of the right angle triangle is 13 Right?

The next thing to do is notice that u have A and H, in the Cos equation from the SOH CAH TOA, then u know that Cos (desired angle) = A/H

So arc Cos (A/H) = Angle...

Hope that helps.

 

[Streetwolf]

Do you not know what arccos means?

Arccos = inverse of cosine or cos^(-1) x

In other words since cos(pi/3) = 0.5 it follows that arccos(0.5) = pi/3.

 

[flyingforever]

a 20 foot long ladder is leaning against a vertical wall such that the base of the ladder is 13 feet from the wall. what angle does the ladder make with the ground?

a. arcsin(13/20)
b. arccos(20/13)
c. arctan(13/20)
d. arctan(20/13)
e. arccos(13/20)

answer is e. but i am completely lost to go about answering this question with the arcs. if it was only cos,sin, tan then I could solve it but i am lost here.

Draw the right triangle. 20 being the hypotenuse and 13 being the adjacent side.