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# help with 3 questions?

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84
7
+1656

i tried doing them myself but i am having diffcutly. Can someone help me?

Feb 5, 2020

#1
+109061
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(1)

Conversion  from  radians  to  degrees :

radian measure   *   180 /  pi

So

pi  *  180  / pi     =   180°

pi/4  * 180 / pi  =   180 / 4  =  45°

5pi/4  *  180 / pi  =   180 * 5 / 4   =  45 * 5  =  225°

11pi / 6  * 180 /pi  =   11*180 / 6  =  11 * 30  =  330°

5 pi / 3  *  180 / pi   =  5 * 180 / 3  =  5 * 60  =  300°

Feb 5, 2020
#4
+1656
+1

ohh okay, this was pretty easy to do. It was just the matter of using the equation! Makes sense now. Thank you

jjennylove  Feb 5, 2020
#2
+109061
+1

(2)

Here's an easy  way to  remember  where the trig functions are positive

Fourth Quadrant : Cosine , Secant

Or  :  ASTC  =  "All Students Take Calculus "

So

The tangent is negative in Q4

The cosine is positive in Q1

The cotangent is positve in Q3

Feb 5, 2020
#5
+1656
+1

Thats a really easy way to remember , i will write this down and try remebering it that way. thank you

jjennylove  Feb 5, 2020
#3
+109061
+2

(-5, 2√7)   =  (x , y)  = [ - 5, √(4 *7) ]   =  (  -5 , √28   )

r =  √[ x^2 + y^2]

cos B  =  x  / r    =  -5 / √[ (-5)^2 + (√28  )^2 ]  =  -5 / √ [25 + 28]  =  -5 / √ 53

Note that  we can also rationalize  this  as

-5√53

____ =    cos B

53

Feb 5, 2020
#6
+1656
+1

This one was more diffcult for me ,but it makes sense now. Thanks

jjennylove  Feb 5, 2020
#7
+109061
+1

OK,  thanks Jenny.....hope all this helped   !!!!

Feb 5, 2020