SOLUTION: How do you write this number in terms of i: {{{ sqrt ( -81 ) }}} ?

Algebra ->  Trigonometry-basics -> SOLUTION: How do you write this number in terms of i: {{{ sqrt ( -81 ) }}} ?      Log On


   

Question 523075: How do you write this number in terms of i: +sqrt+%28+-81+%29+ ?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
How do you write this number in terms of i: sqrt%28-81%29
Write it:
sqrt%2881%2A-1%29
extract the square root of 81:
9%2Asqrt%28-1%29
we know the square root of -1 = i, therefore we have
9i