Double Angle Formulas help

Hey,

Show that:

tanx + cotx = 2cosec2x

But the = is three lines (no button on the keyboard).

Cheers :smile:

Write the LHS out in terms of sin and cos, and then put it over a common denominator
i.e. a/b + b/a = (a^+b^2) /(ab)

....that gets you the answer.

Reply 2

v-zero

Those three lines mean it is always equal to. Try turning cosec(2x) in something with only x (not 2x), using the sin double angle formula.

Reply 3

Waheyyyy

TheDuck

Write the LHS out in terms of sin and cos, and then put it over a common denominator
i.e. a/b + b/a = (a^+b^2) /(ab)

....that gets you the answer.

Thanks, but it's: sinx/cosx + 1/tanx

To get it in terms of sin/cos would I put the second part as 1/(sinx/cosx)? Not sure how that would work :confused:

Reply 4

darkness9999

Waheyyyy

Thanks, but it's: sinx/cosx + 1/tanx

To get it in terms of sin/cos would I put the second part as 1/(sinx/cosx)? Not sure how that would work :confused:

yes thats correct ... so its cos/sin... multiply through and then ull get ur answer