How do you implicitly differentiate -3=xsecy3=xsecy?

1 Answer
Jul 21, 2016

(dy)/(dx)=-xcotydydx=xcoty

Explanation:

When we implicitly differentiate a function f(y)f(y), we first differentiate f(y)f(y) with respect to yy and then multiply by (dy)/(dx)dydx. This comes from chain rule as (df)/(dx)=(df)/(dy)xx(dy)/(dx)dfdx=dfdy×dydx.

Now using product rule for differentiating 3=xsecy3=xsecy, we get

0=x xxsecy+1xxsecytany(dy)/(dx)0=x×secy+1×secytanydydx or

secytany(dy)/(dx)=-xsecysecytanydydx=xsecy or

(dy)/(dx)=(-xsecy)/(secytany)dydx=xsecysecytany

= (-xcancel(secy))/(cancel(secy)tany)

= -xcoty