2.9 Calculus of Hyperbolic Functions

[STARTS AT 13:47]

INSTRUCTOR: OK, next, hyperbolic cosine inverse. OK, now, we have to make sure we take the derivative of that 3x as we go, all right? So the derivative of hyperbolic cosine inverse is 1 over square root of u squared. So this will be 3x squared minus 1 times the derivative of that inside function, which is 3. So let's make that 3 over the square root of 9x squared minus 1. 

All right, hyperbolic contingent inverse. OK, now notice that's actually the inside function there. So let's use the chain rule first. 3 hyperbolic inverse cotangent squared times the derivative of the hyperbolic cotangent inverse, which is 1/1 minus x squared, the same as the inverse tangent. So I'm going to go ahead and write that here. OK? Over 1 minus x squared.

[ENDS AT 15:07]