Question

Алгебра 10 класс Срочно! ! ! ! ! ! ! решите номера а4 в1 в2 в3

Answer 1

b.1     tgα·ctgα = 1; ctgα =1÷tgα = 5/12;  ctgα =5/12;  
1 + tg²α =1/cos²α ;  1+ 144/25 = 1/cos²α
169/25 =1/cos²α;  cosα= 5/13; sinα = 12/13;
b.2    $= frac{2(sin alpha - cos alpha )}{2cos alpha + 3sin alpha} /cos alpha ; 2(tgα - 1)/2+3tgα = 2(2/5 -1)/2+3*2/5= 1,2 ÷3,2 = 0,375; b.3  1 + [tex] frac{3(1 - x^{2} cos^{2} alpha }{1 + x^{2} tg^{2} alpha } = frac{1+ tg^{2} alpha +3( cos^{2} alpha +sin^{2} alpha - cos^{2} ) }{1+ tg^{2} alpha } =1 +3 sin^{2} alpha cos^{2} alpha alpha$