化简:sin^2(42°+α)-2tan(25°+α)tan(65°-α)+sin^2(48°-α)-cot^2(990°-α)

化简cos^2(-α)-[tan(360°+α)/sin(-α)] 化简:sin^2(42°+α)-2tan(25°+α)tan(65°-α)+sin^2(48°-α)-cot^2(990°-α) 化简：(sin^2α-tan^2α)/(sin^2α·tan^2α) 化简：(sin²αtanα+cos²α/tanα+2sinαcosα)sinαcosα 若a属于(0,π/2)试比较tanα、tan(tanα)、tan(sinα) (cot^2)α((tan^2) α-(sin^2) α) 化简 化简(sin2α+2sin^2α)/(1-tanα) 化简cos2(-α)-tan(2π+α)/sin(-α) 已知tanα=2,sinα 化简(sinα)^2tanα+cosα+(cosα)^2*1/tanα+2sinαcosα 化简sin^2(42°+b)-2tan(45°+b)tan(45°-b)+sin^2(48°-b)-cot^2(270°-b) 化简：(cosα/2-sinα/2)(cosα/2+sinα/2)(1+tanαtanα/2) 化简sin^2α*tanα+cos^2α*1/tanα+2sinα*cosα 化简:sin^2α*tanα+(cos^2α)/(tanα)+2sinαcosα 只要结果 化简cos(α -π )tan(α-2π)tan(2π-α)/sin(π+α) cos(π-α)tan(2π-α)tan(π-α)/sin(π+α) 化简 化简sin(2π-α）tan（α+π）tan（-α-π）/ 化简：sin^2α×tanα+cos^2α×cotα+2sinα×cosα