Poobah Posted March 29, 2009 Share Posted March 29, 2009 could this be a typo? in a question sheet? 2cosecx-1=0??? Link to comment Share on other sites More sharing options...
max.yevs Posted March 29, 2009 Share Posted March 29, 2009 (edited) Ah ok poobah, yeah i realized its csc right after i posted the first time [math]2csc(x) - 1 = 0[/math] [math]{\frac{1}{sin(x)}} = 0.5[/math] [math]sin^{-1}(x) = 2[/math] [math]x = sin(2)[/math] [math]x = no solution[/math] as you can see then there are no solutions (since sin(x) is 1 at max.) Edited March 29, 2009 by max.yevs Link to comment Share on other sites More sharing options...
Poobah Posted March 29, 2009 Author Share Posted March 29, 2009 No - written as....... 2csc-1=0 Merged post follows: Consecutive posts mergedas i thought - unsolveable - prob just a typo - but ty Link to comment Share on other sites More sharing options...
the tree Posted March 29, 2009 Share Posted March 29, 2009 [math]sin^{-1}(x) = 2[/math] [math]x = sin(2)[/math] [math]x = no solution[/math] as you can see then there are no solutions (since sin(x) is 1 at max.) sin(2) definitely has a value, approximately 0.9. Link to comment Share on other sites More sharing options...
Bignose Posted March 29, 2009 Share Posted March 29, 2009 Ah ok poobah, yeah i realized its csc right after i posted the first time [math]2csc(x) - 1 = 0[/math] [math]{\frac{1}{sin(x)}} = 0.5[/math] [math]sin^{-1}(x) = 2[/math] [math]x = sin(2)[/math] [math]x = no solution[/math] as you can see then there are no solutions (since sin(x) is 1 at max.) This is the step you got wrong... [math]sin^{-1}(x) = 2[/math] as tree pointed out, there is an x that solves this step -- you took the inverse of the sine function too early... [math]2\csc x -1 =0[/math] [math]2\frac{1}{\sin x} = 1 [/math] [math]\frac{1}{\sin x} = \frac{1}{2}[/math] [math]\sin x = 2[/math] and now you conclude that x has no solution because sin is limited to values between -1 and 1. Link to comment Share on other sites More sharing options...
max.yevs Posted March 29, 2009 Share Posted March 29, 2009 ah right... that's what happens when you go from step1 to step 2 in your head... Link to comment Share on other sites More sharing options...
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