# Exponents in equation causing a decimal problem

Its been a long time since I've had to do math and I'm now trying to complete an advanced radio course. I've been doing not too bad until I came to this question that seems to be giving my an exponential problem! I know of others doing the same self study program have had the same issue. It would be nice to learn how this should really work. So here goes: The equation given to solve the question is (it's not my equation so I can't change it): C=1/(2pi *f)E2 * L

Here is some reference: that you all probably already knowing: C=Capacitance f=frequency in hertz L= inductance in henry 1 Pico Farad = 1*10E-12 farad 1 MHz = 1*10E6 hertz

## The sample test question is:

What is the value of capacitance (C) in a series R-L-C circuit, if the circuit resonant frequency is 14.25 MHz and L is 2.84 microhenrys?

So it's my understanding then that my answer should be 4.4 e-11 but I'm getting 4.4 e-14 which is way smaller a number than it should be. This is my equation as entered in my calculator (I might have more brackets than some of you think I need but my calculator seems to want it this way): 1/(((2pi)*(14.25*10E6))E2*(2.84*10E-6)) This is my answer: C=4.392302014589E-14 And that would be the same as C=.0044 picofarads instead of C=44 picofarads.

I hope I explained this clearly enough. Thanks in advance for your help.

• When you write your fractions with slashes, please incorporate parentheses to show the $*L$ is in the denominator, not the numerator. Commented Aug 28, 2016 at 16:13

You are misinterpreting the equation with the $E2$, maybe it is a typo in your book. The usual expression is $f=\frac 1{2 \pi \sqrt{LC}}$, so maybe the $E2$ is supposed to be a square. This gives $C=\frac 1{(2\pi f)^2L}$ which duly gives $4.4E-11$ farads.