lucky+five+since1997
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邬贺19113775548:
高一数学 cos^2(π/5)+sin^2(π/10) 求值 -
37098季星
: 高一数学 cos²(π/5)+sin²(π/10) 求值 解:先求cos(π/5),即cos36⁰的值.cos36⁰=1-2sin²18⁰;又cos36⁰=sin54⁰=3sin18⁰-4sin³18⁰;故得1-2sin²18⁰=3sin18⁰-4sin³18⁰;即有4sin³18⁰-2sin²18⁰-3sin18⁰+1=0 分解因式:4...
邬贺19113775548:
诱导公式相关习题 用诱导公式写出过程 1.sin115° 2.cos95°3.cosπ/5+cos2π/5+cos3π/5+cos4π/54.tan10°+tan170°+sin1866° - sin( - 606°)5.sin( - α - 5π)*cos(α - π/2) - ... -
37098季星
:[答案] 1.sin115° =sin(90° +25° )=cos25° 2.cos95°=cos(90° +5° )=-sin5° 3.cosπ/5+cos2π/5+cos3π/5+cos4π/5=cosπ/5+cos2π/5+cos(π-2π/5)+cos(π-π/5)=cosπ/5+cos2π/5-cos2π/5-cosπ/5=04.tan10°+tan170°+sin1866°-sin(-606°)=tan10° +tan(180° -10° )+sin(...
邬贺19113775548:
C语言:程序功能是:对x=1,2,3,……10,求f(x)=x*x - 5*x+sin(x)的最大值 -
37098季星
: 1-5+sin(1) //下面for从2开始说明默认最大值为f(1) x*x-5*x+sin(x)>max
邬贺19113775548:
化简:[cos(α - 5π)+2sin(3π - α)]/[csc(3π+α)+sec(5π+α)] -
37098季星
:[答案] [cos(α-5π)+2sin(3π-α)]/[csc(3π+α)+sec(5π+α)]=[cosacos5π+sinasin5π+2(sin3πcosa-cos3πsina)]/[1/sin(3π+a)+1/cos(5π+a)]=[-cosa+2sina]/[-1/sina-1/cosa]=(-cosa+2sina)*sinacosa/(-cosa-sina)=(-1...
邬贺19113775548:
函数y=sin(2x+5π2)的图象的对称轴方程是______. -
37098季星
:[答案] ∵y=sin(2x+ 5π 2)=cos(2x), 又∵余弦函数y=cosx的对称轴方程是x=kπ,k∈Z, ∴函数y=sin(2x+ 5π 2)=cos(2x)的图象的对称轴方程是2x=kπ,k∈Z, 即x= kπ 2(k∈Z), 故答案为x= kπ 2(k∈Z).
邬贺19113775548:
y=sin(3x+5)的导数怎么求 -
37098季星
:[答案] y'=sin'(3x+5)*(3x)'=3cos(3x+5)
邬贺19113775548:
6! - 5! - 4! - 3! - 49+sin兀/2=多少 -
37098季星
: 6!-5!-4!-3!-49+sin(π/2)=720 -120-24-6 -49 +1=522
邬贺19113775548:
已知a是第一象线的角,且cosa=5/13,求sin(a+π/4)/cos(2a+4π) -
37098季星
:[答案] 已知a是第一象限的角,且cosa=5/13,求sin(a+π/4)/cos(2a+4π)sin(a+π/4)/cos(2a+4π)=(√2/2)(sinα+cosα)/cos2α=(sinα+cosα)/(cos²α-sin²α)=1/(cosα-sinα)=1/[5/13-√(1-25/169)]=1/[(5/13)-(12...
邬贺19113775548:
直角坐标方程3x - 4y+5=0的极坐标方程为 直角坐标方程x^2+y^2+2x=0的极坐标方程为 -
37098季星
: 将x=pcosθ, y=psinθ代入即可得到.3x-4y+5=0的极坐标方程为:3pcosθ-4psinθ+5=0 x^2+y^2+2x=0的极坐标方程为:p^2+2pcosθ=0, 简化为:p+2cosθ=0
邬贺19113775548:
y=x+z+5如何用c语言编程 -
37098季星
: #include int main() { int x,y,z; printf("请输入x,z:"); scanf("%d%d",&x,&z); y=x+z+5; printf("y的值为%d\n",y); }