Shaomada

avatar
UsernameShaomada
Score66
Membership
Stats
Questions 1
Answers 16

 #1
avatar+66 
+5

http://web2.0calc.com/ is a calcutator.

Enter $$556 \div 4$$ or $$556/4$$ and it will correctly compute $$\frac{556}{4}=139$$.

Mar 15, 2015
 #1
avatar+66 
+5

the site you are posting this on (http://web2.0calc.com/) is a calculator. Press the button which has 'cos' printed on it, 3 times the '1' button, 1 time the '0' button and finally one time the ')' button. The top field should now show cos(1110). Make sure you have degree selected in the button left and press '='. The calculator will now correctly calculate $$cos(1110^\circ)=0.866025403784$$. Easy if you know how to use a calculator.

Mar 15, 2015
 #1
avatar+66 
+5

This depends on what exactly you understand as an exponential equation and what you can use. I will asume you mean an equation with only one unknown, which I will call $$x$$, in which x will only appear in exponents such as $$2^x$$ or $$e^x$$.

If you have a computer, you might just want to use a programm solving the equation approximativly, you dont even need any fancy software, for example you can just let GeoGebra plot both sides of the equation and then intercect the graphs. There are probably better ways, but this should work.

(Edit: I just saw you can even use this calcutator, for example if you want to solve the equation $$2^x=8$$ enter "solve(2^x=8)" in the calculator and it will compute you the solution)

If you only have a standard calculator, try to change the form  of your equation till it looks like $$e^x=y$$ where you know the value of $$y$$ and are looking for the value of $$x$$ (If you find yourself unable to do so, either the assingment is different than I expected from your question or you should look up rules/laws of expontents). Then $$x = \ln y$$ is an equivalent eqution. Just use your calculator to approximatly calculate the right side.

If you have a table of logarithms, proceed as in the point before, but look the logarithm up instead of using a calculator.

If you have none of the tools mentioned, use that $$e^x$$ gets bigger the bigger $$x$$ gets. Change the form of the equation as allways, and then systimaticly try out values.

 

I will mention a few more special forms of exponential equations, but I don't know an easy way to just solve any equation which contains exponentials.

If you have an equation of the form $$e^{f(x)}=y$$, for example $$2^{2x+1} = 8$$, first solve the equation $$e^z = y$$, which will give you $$z=3$$ in the example, then solve the equation $$f(x) = z$$, so $$2x+1=3$$ in our example.

If $$x$$ is not a real but a complex number, just split it in its real and its imaginary part, corresponding to magnitude and phase of $$y$$.

Mar 15, 2015