Implicitly differentiate expression. {{COMMENT_4}} {{CMD_5}} Find the equation of the tangent line for curves that are not plots of functions. {{CMD_6}} Understand how changing the variable changes how we take the derivative. {{CMD_7}} Understand the derivatives of functions that are not defined explicitly in terms of an independent variable . {{CMD_8}} Explain the formula for the derivative of the natural log function. {{CMD_9}} Calculate derivatives of logs in any base. {{CMD_10}} Calculate the derivative of an exponential function, {{MATH_11}}, where {{MATH_12}}. {{CMD_13}}