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Prove that：tan-11/3+tan-11/5+tan-11/7+tan-11/8=45°
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Prove that：(sin75°+sin15°)/(sin75°-sin15°)=tan60°
Given ∠1=∠2,a,b,c，find d.
Transform the difference of two squares into a rectangle, the ratio of two sides being 2 : 3.
With BC, one leg of △ABC, as diameter, a circle is described intersecting the hypotenuse AC at P. From P draw a tangent intersecting AB at D. Showt hat AD = BD.
Show that the line joining the mid-points of the diagonals of a trapezoid is half the difference of its bases.
Evaluate to four significant figure by logarithm,
Simplify yz(x+a)/(x-y)(x-z)+zx(y+a)/(y-z)(y-x)+xy(z+a)/(z-x)(z-y)
Determine the real value of k, so that the roots of equation, (k - 1)x² - kx - 2x + 4 = 0, may be real and equal.
Solve and verify x²+3x-6(x²+3x-3)1/2+2=0
圣约翰大学幂函数
函数y=cosx+1(-π≤x≤0)的反函数是【 】
设x=sinα,且α∈[-π/6,5π/6]，则arccosx的取值范围是________.
函数f(x)=sinx,x∈[π/2,3π/2]的反函数f-1(x)=【 】
计算3/2 cos-1+1/4 sin-1(2√2π)/(2+π2 )+tan-1(√2/π)的值为__________.
英：Prove that汉：证明tan-1(3/4)=2 tan-1(1/3)
求证下列恒等式tan-1m+tan-1n=tan-1(m+n)/(1-mn)
试证下列恒等式2 sec-1x=tan-1
设α=4π/3，则arccos(cosα)的值是【 】
设 |a|≤1，求arccosa+arccos(-a)的值.
当x∈[0,1]时，在下面关系式中正确的是【 】
函数y=sin(2x+5π/2)的图像的一条对称轴方程是【 】
设5π<θ<6π,cos(θ/2)=a，那么sin(θ/4)等于【 】
如果下图是周期为2π的三角函数y=f(x)的图象，那 么f(x)可以写成【 】
如果函数y=sin(ωx)cos( ωx)的最小正周期是4π，那么常数ω为【 】
函数y = (1 - tan22x)/(1 + tan22x)的最小正周期是【 】
在直角三角形中两锐角为A和B，则sinAsinB【 】
设θ是第二象限的角,则必有【 】
sin600°的值是【 】
在△ABC中，a,b,c分别是角A,B,C的对边，设a+c=2b,A-C=π/3，求sinB的值.以下公式供解题是参考：sinθ+sinφ=2sin (θ+φ)/2 cos (θ-φ)/2，sinθ-sinφ=2cos (θ+φ)/2 sin (θ-φ)/2,cosθ+cosφ=2cos (θ+φ)/2 cos (θ-φ)/2,cosθ-cosφ=-2sin (θ+φ)/2 sin (θ-φ)/2.
若0<α<β<π/4,sinα+cosα=a,sinβ+cosβ=b，则【 】
