+0  
 
+5
69
2
avatar

sec[sin^-1(4/7)]

Guest Mar 9, 2017

Best Answer 

 #1
avatar+79881 
+5

We're looking for the secant of an angle whose sin = 4/7

 

Sec =  r /x    and x  =  sqrt (7^2 - 4^2)   = sqrt (49 - 16)  = sqrt (33)

 

So.....sec  (theta)   = 7 / sqrt(33)   =  (7/33)*sqrt(33)

 

[Since the sine inverse only has a range of -pi/2 to pi/2, theta must fall in either the 1st or 4th quadrant......so......the secant is positive in both of these ]

 

 

cool cool cool

CPhill  Mar 9, 2017
Sort: 

2+0 Answers

 #1
avatar+79881 
+5
Best Answer

We're looking for the secant of an angle whose sin = 4/7

 

Sec =  r /x    and x  =  sqrt (7^2 - 4^2)   = sqrt (49 - 16)  = sqrt (33)

 

So.....sec  (theta)   = 7 / sqrt(33)   =  (7/33)*sqrt(33)

 

[Since the sine inverse only has a range of -pi/2 to pi/2, theta must fall in either the 1st or 4th quadrant......so......the secant is positive in both of these ]

 

 

cool cool cool

CPhill  Mar 9, 2017
 #2
avatar+5565 
+6

Hmmmmm! I think I understand these better now after reading this! :)

hectictar  Mar 9, 2017

4 Online Users

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details