Theorem logcxpd

Description: Logarithm of a complex power. (Contributed by Mario Carneiro, 30-May-2016)

	Ref	Expression
Hypotheses	rpcxpcld.1	$$⊢\phi \to A\in {ℝ}^{+}$$
	rpcxpcld.2	$$⊢\phi \to B\in ℝ$$
Assertion	logcxpd	$$⊢\phi \to \log A^B=B\log A$$

Proof

Step	Hyp	Ref	Expression
1		rpcxpcld.1	$$⊢\phi \to A\in {ℝ}^{+}$$
2		rpcxpcld.2	$$⊢\phi \to B\in ℝ$$
3		logcxp	$$⊢\left(A\in {ℝ}^{+}\wedge B\in ℝ\right)\to \log A^B=B\log A$$
4	1 2 3	syl2anc	$$⊢\phi \to \log A^B=B\log A$$