Question

TRIG HW; find missing side by using trignometry

Answer 1

Answer:

Step-by-step explanation:

Use SOH CAH TOA to recall how the trig functions fit on a triangle

SOH: Sin(Ф)= Opp / Hyp

CAH: Cos(Ф)= Adj / Hyp

TOA: Tan(Ф) = Opp / Adj

the above is really helpful if you don't have a brain.  :P

for 7 we only need Pythagoras's theorem, know it?

$c^{2}$ = $a^{2}$ + $b^{2}$

out of curiosity.. does the above formula seem "impossible" ?  or does it make sense?

$c^{2}$ = $12^{2}$ + $16^{2}$

$c^{2}$ = 144 + 256

$c^{2}$ = 400

c = $\sqrt{400}$

c = 20

x= 20

for 8 we do need the above list of trig functions. we want to find the Hyp x and we know an angle and the adjacent side sooo use Cos .. b/c we can see it's got those parts in it

Cos(60) = 18 / x

I'll show you the algebra we need to use to get this formula so that we can find x

A = B / x  ( this is how it looks above )

x = B / A    , now just put in the parts

x = 18 / Cos(60)  now solve it w/ your calculator..  :P Cos(60) happens to be 1/2 so you could have done this w/o your calculator   :/

x = 36

there you go,   :)