Question

prove the above........

Do not use the following formula.
[a3 - b3 = (a - b)(a2 + ab + b2)]

prove that by another formula......​

Answer 1

Answer:

I hope it is helpful to you...

Step-by-step explanation:

a³-b³=(a-b) ³+3ab(a-b)

a³-b³=(a-b) [(a-b)²+ 3ab]

tan³©-1/tan © - 1

=(tan©-1)[(tan©- 1)²+3tan©]\tan ©-1

=(tan© - 1)²+3tan ©

=tan²©+1-2tan©+3tan©

=tan²©+1+tan ©

{tan²©+1=sec²©}

= sec²©+tan©

Answer 2

Answer:

I hope it's helpful to you.............

.............. and it is correct