Using a calculator to compute logarithms (optional) In this question, we introduce a useful formula for logarithms, which is actually beyond the scope of the unit - but very useful nonetheless. It is often called the change of base formula. logb(n)=loga(b)loga(n) (a) Use the change of base formula to write log5(6) as a fraction of logarithms base 10 (that is set a to 10 in the formula). (b) On a calculator (such as on your phone), you will have a log button, which calculates logarithms in base 10. Compute log5(6) using your formula from above. (c) You can use this formula to convert your answers in question (4) from logarithmic form to numerical form, if you wish. This will enable you to check your answers by substituting back into the equation to see if it holds true