trigonometric limit

[MoemenKhallaf]

I can't compute the following question

Find lim┬(x→0)⁡〖cos⁡〖(π/12+2x)-2cos(π/12+x)+cos⁡〖π/2〗 〗/x^2 〗

Thanks

 

[Deleted member 4993]

I can't compute the following question

Find lim┬(x→0)⁡〖cos⁡〖(π/12+2x)-2cos(π/12+x)+cos⁡〖π/2〗 〗/x^2 〗

Thanks

Your graphics are not visible - at least to "micro-soft" eye.....

 

[stapel]

Find lim┬(x→0)⁡〖cos⁡〖(π/12+2x)-2cos(π/12+x)+cos⁡〖π/2〗 〗/x^2 〗

I don't know what the subscripted "T" in the limit might be, nor what might be the significance of the oddly-placed brackets. I think the exercise is meant to be as follows:

. . . . .\(\displaystyle \displaystyle \mbox{Find }\, \lim_{x\, \rightarrow \, 0}\, \dfrac{\left[\cos \left(\, \dfrac{\pi}{12}\, +\, 2x\, \right)\, -\, 2\cos\left(\, \dfrac{\pi}{12}\, +\,x\, \right)\, +\, \cos\left(\dfrac{\pi}{2}\right)\, \right]}{x^2}\)

Please confirm or correct. When you reply, please include a clear listing of your efforts so far. Thank you!

 

[MoemenKhallaf]

I don't know what the subscripted "T" in the limit might be, nor what might be the significance of the oddly-placed brackets. I think the exercise is meant to be as follows:

. . . . .\(\displaystyle \displaystyle \mbox{Find }\, \lim_{x\, \rightarrow \, 0}\, \dfrac{\left[\cos \left(\, \dfrac{\pi}{12}\, +\, 2x\, \right)\, -\, 2\cos\left(\, \dfrac{\pi}{12}\, +\,x\, \right)\, +\, \cos\left(\dfrac{\pi}{2}\right)\, \right]}{x^2}\)

Please confirm or correct. When you reply, please include a clear listing of your efforts so far. Thank you!

hanks
i think the question as new photo
regards

 

[stapel]

I think the exercise is meant to be as follows:

. . . . .\(\displaystyle \displaystyle \mbox{Find }\, \lim_{x\, \rightarrow \, 0}\, \dfrac{\left[\cos \left(\, \dfrac{\pi}{12}\, +\, 2x\, \right)\, -\, 2\cos\left(\, \dfrac{\pi}{12}\, +\,x\, \right)\, +\, \cos\left(\dfrac{\pi}{2}\right)\, \right]}{x^2}\)

Please confirm or correct. When you reply, please include a clear listing of your efforts so far.

hanks

Okay; thank you for confirming that my interpretation was correct. Now please reply showing your work so far. Did you apply any trig identies? If so, which, and where did they lead? If not, what did you try?

Please be complete, even if you think it's wrong. Thank you!