tan(3π+α)=2;-》tanα=2;
sinα=2(根号5)/5;
cosα=(根号5)/5;
或
sinα=-2(根号5)/5;
cosα=-(根号5)/5;
1.、(sinα+cosα)²=(3/(根号5))²=9/5;
2.sinα-cosα/2sinα+cosα=sinα+cosα-1/(2tanα)=±(3(根号5)/5)-1/4;
=(3(根号5)/5)-1/4;
或者=-(3(根号5)/5)-1/4;
tan(3π+α)=2;-》tanα=2;
sinα=2(根号5)/5;
cosα=(根号5)/5;
或
sinα=-2(根号5)/5;
cosα=-(根号5)/5;
1.、(sinα+cosα)²=(3/(根号5))²=9/5;
2.sinα-cosα/2sinα+cosα=sinα+cosα-1/(2tanα)=±(3(根号5)/5)-1/4;
=(3(根号5)/5)-1/4;
或者=-(3(根号5)/5)-1/4;