Differentiating Logarithmic Functions without Base e
Key Questions
-
By Change of Base Formula:
log_bx={log_ax}/{log_ab} ,y=log_3x={lnx}/{ln3} By taking the derivative,
y'={1/x}/{ln3}=1/{(ln3)x} -
Answer:
-tan(x)/ln(2) Explanation:
f(x)=log_2(cos(x))=ln(cos(x))/ln(2) 1/ln(2) is just a constant and can be ignored.(ln(u))'=(u')/u u=cos(x), u'=-sin(x) f'(x)=1/ln(2)*(-sin(x))/cos(x)=-tan(x)/ln(2) -
Change of Base Formula
log_bx={log_ax}/{log_ab} ,where
a is any positive number except1 .I hope that this was helpful.