Let x>0x>0x>0, a>0 a>0\,a>0 and a≠1a\ne1a=1. Let k k\,k be a real number for which xk x^k\,xk is defined.
Starting from the definition of a logarithm, prove that loga(xk)=klogax\log_a(x^k)=k\log_a xloga(xk)=klogax.
8 exam-style questions on WJEC A Level Maths 1.1.1 Proof. Each one has a worked solution and a mark scheme showing where the marks go.