sin[(π/4)+α]等于多少,诱导公式推导详细过程

sin[(π/4)+α]等于多少,诱导公式推导详细过程

sin3/4兀等于√2/2。结果计算过程：sin(3π/4)=sin(π/4)=sin45°=√2/2。sin45°表示的是角度为45°的角的对边与斜边之比。扩展资料：正弦（sine），数学术语，在直角三角形中，sin(a+b)=sinacosb+cosasinb 令a=α,b=π/4sin(+α)=sinαcos+sincosα=(√2)/2(sina+cosa) sin(a+b)=sinacosb+cosasinb 令a=α,b=sin(+α)=sinαcos+sincosα=(sina+cosa)结果

1/(sinx+cosx)的不定积分是多少？具体回答如下：∫1/(sinx+cosx) dx。∫1/[√2(sinxcosπ/4+sinπ/4·cosx)]dx。∫1/[√2sin(x+π/4)] dx。√2/2 ∫csc(x+所以sin(a-π/4)=±3/5 α是第四象限角，cosα=3/5则cos(α-4/π)=? 应该是cos(α-π/4)吧cosα=3/5,sinα=-4/5 cos(α-π/4)=cosαcosπ/4+sinαsinπ/4=(3/

ˇωˇ 解(1) 确定阶数N ksp=100.1αp-1100.1αs-1=0.0242 λsp=2πfs2πfp=2.4 N=-lg0.0242lg2.4=4.25,取N=5 (2) 由式(3.3.15),其极点为p0=ej35π,p1=ej45π,p2=ejπ, p3=ej65π,psin(π/4+α)=√2/2cosa+√2/2sinasin(π/4-α)= √2/2cosa-√2/2sinacos(π/4+α)=√2/2cosa-√2/2sinacos(π/4-α)=√2/2cosa+√2/2sinatan(π/4+α)=(1+tan

sin(x + π/4)=sin(x)(\sqrt{2}/2)+cos(x)(\sqrt{2}/2)又因为：sin²x + cos²x=1故可得：sin(x + π/4)=(2sin xcos x + cos²x)/\sqrt{2}而当x=0,sin(x + π/4)sin(α+π/4)=sinα×cosπ/4+cosα+sinπ/4 =√2/2(sinα+cosα)三角函数的和角公式：又称三角函数的加法定理，是几个角的和（差）的三角函数通过其中各个角的三