Question

Solve the equation, if possible. Give your answer in radical form. t^2=-81

Answer 1

\(\bf {\color{blue}{ a^2-b^2 = (a-b)(a+b)}}
\\ \quad \\ \quad \\
t^2=-81\implies t^2+81=0\implies t^2+9^2=0\\ \quad \\
{\color{blue}{ (t-9)(t+9)}}=0\)

Answer 2

ahemm rats... I got my signs mixed up... heeh. that's .. off.. one sec

Answer 3

well, actually you'd get a complex anyhow if you just take root to both sides

Answer 4

\(\bf t^2=-81\implies \sqrt{t^2}=\sqrt{-81}\implies t=\sqrt{-9^2}\\ \quad \\
t=\sqrt{9^2\cdot -1}\implies t=\sqrt{9^2}\cdot \sqrt{-1}\)

Answer 5

is that in radical form??????

Answer 6

-81 = -1 x 81
rt -81 = rt-1 rt 81
rt(t^2) = rt(-81) =(rt-1)(rt 81)
rt-1 =i rt 81 = + or - 9

Answer 7

Thank you to both of you!!!

Answer 8

welcome

Answer 9

yw

Answer 10

\[t^2=-81\]
\[t=\pm \sqrt{-81}\]
\[t=\pm9i\]