Given matrices A and B shown below, find (−3)A+(−5)B.
1 answer:
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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?
=
+
out of curiosity.. does the above formula seem "impossible" ? or does it make sense?
=
+
= 144 + 256
= 400
c =
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, :)