Question

cos60°+sin45°×cos45°-tan60°×tan30°=？？

cos45°-cos60°分之1+sin30°分之1+cos²30°+sin²45°=？？
3tan30°+cot45°+cos30°+2sin60°-2tan45°=？？
要详细过程！！谢谢！！

Answer 1

cos60°+sin45°×cos45°-tan60°×tan30°=1/2+√2/2×√2/2-√3×√3/3=1/2+1/2-1=0
cos45°-cos60°分之1+sin30°分之1+cos²30°+sin²45°=√2/2-1/（1/2）+1/（1/2）+（√2/2）^2
=√2/2+1/2=(√2+1)/2
3tan30°+cot45°+cos30°+2sin60°-2tan45°=3*√3/3+1+√3/2+2*√3/2-2=1+1-2+√3/2+√3=3√3/2

Answer 2

cos60°+sin45°×cos45°-tan60°×tan30°
=1/2+(√2)/2×(√2)/2-√3×(√3)/3
=1/2+1/2-1
=0

cos45°-cos60°分之1+sin30°分之1+cos²30°+sin²45°
=(√2)/2-2+2+3/4+1/2
=(2√2)/4+3/4+2/4
=(2√2+5)/4

3tan30°+cot45°+cos30°+2sin60°-2tan45°
=√3+1+(√3)/2+√3-2
=(5√3)/2-1

Answer 3

几点放开了吧

Answer 4

√2/2-2+2+(√3/2)*(√3/2)+√2/2=√2+3/4
√3+1+√3/2+2*√3/2-2=5√3/2-1