As part of the DTU outreach activities towards high schools, Peter gave a guest lecture on solving cubic polynomial equations. The activities are organized within the framework of an InterMat workshop (see https://matematicum.dtu.dk/intermat for information. Danish only). With various high school students listening online, an explanation was given on how to use Tschirnhaus transforms to obtain the famous Cardano solution formulas. The same method can be used to solve the quartic equation.