+0  
 
0
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avatar+157 

find the exact value without using a calculator

sec 150°

cos 300°

csc (-3π/4)

 Apr 19, 2016
 #1
avatar+129852 
+5

sec(150°)  = 1/ cos (150° )  = 1 / [ -√3 / 2]  =    -2 / √3 

 

cos(300°) =  1/2

 

csc (-3pi / 4)  =  csc (-135°)  = csc(360° - 135°)  = csc ( 225° )  =

1 / sin (225°)  = 1 / [-1 / √2 ]  =  - √2

 

 

cool cool cool

 Apr 19, 2016
 #2
avatar+1904 
0

\(sec(150°)\)

 

\(\frac{1}{cos(150°)}\)

 

\(\frac{1}{\frac{-\sqrt{3}}{2}}\)

 

\(1\times(-\frac{2}{\sqrt{3}})\)

 

\(-\frac{2}{\sqrt{3}}\)

 

\(-\frac{2\sqrt{3}}{3}\)

 

 

 

\(cos(300°)\)

 

\(\frac{1}{2}\)

 

 

 

\(csc(-\frac{3\pi}{4})\)

 

\(\frac{1}{sin(-\frac{3\pi}{4})}\)

 

\(\frac{1}{-\frac{\sqrt{2}}{2}}\)

 

\(1\times(-\frac{2}{\sqrt{2}})\)

 

\(-\frac{2}{\sqrt{2}}\)

 

\(-\frac{2\sqrt{2}}{2}\)

 

\(-\sqrt{2}\)

.
 Apr 19, 2016

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