Respuesta :
Answer:
Step-by-step explanation:
Tanx(cotx +tanx)= sec^2x
distribute
tanx cot x + tan ^2 x = sec^2 x
tanx * cot x = sin/cos * cos /sin = 1
tanx cot x + tan ^2 x = sec^2 x
1 + tan ^2 x = sec ^2 x
1 + sin ^2 x/ cos ^2 x = 1 /cos ^2 x
get a common denominator
cos ^2 x/ cos ^2 x + sin ^2 x/cos ^2 x = 1 /cos ^2 x
combine the terms
(cos ^2 x + sin ^2 x) /cos ^2 x = 1 /cos ^2 x
sin ^2 x + cos ^ 2 x =1
1 /cos ^2 x = 1 /cos ^2 x
[tex]\bf tan(x)[cot(x)+tan(x)]~~=~~ sec^2(x) \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \cfrac{sin(x)}{cos(x)}\left( \cfrac{cos(x)}{sin(x)}+ \cfrac{sin(x)}{cos(x)}\right)\implies \cfrac{sin(x)}{cos(x)}\left( \cfrac{cos^2(x)+sin^2(x)}{sin(x)cos(x)}\right) \\\\\\ \cfrac{\underline{sin(x)}}{cos(x)}\left( \cfrac{1}{\underline{sin(x)} cos(x)}\right)\implies \cfrac{1}{cos(x)cos(x)}\implies \cfrac{1}{cos^2(x)}\implies sec^2(x)[/tex]
recall sin²(x) + cos²(x) = 1.