# 1เลือกประเภทtan(60°−30°)=x\tan\left(60\degree-30\degree\right)=xx=tan60°−tan30°1−tan60°tan30°x=\frac{\tan60\degree-\tan30\degree}{1-\tan60\degree\tan30\degree}x=tan60°−tan30°2+tan60°tan30°x=\frac{\tan60\degree-\tan30\degree}{2+\tan60\degree\tan30\degree}x=tan30°−tan30°1+tan60°tan60°x=\frac{\tan30\degree-\tan30\degree}{1+\tan60\degree\tan60\degree}x=tan60°−tan30°1+tan60°tan30°x=\frac{\tan60\degree-\tan30\degree}{1+\tan60\degree\tan30\degree}
# 2เลือกประเภทsin140°cos250°+sin70°cos320°=x\sin140\degree\cos250\degree+\sin70\degree\cos320\degree=xx=sin(70°+40°)x=\sin\left(70\degree+40\degree\right)x=sin30°x=\sin30\degreex=cos(70°−40°)x=\cos\left(70\degree-40\degree\right)x=cos30°x=\cos30\degree
# 3เลือกประเภทtanA−tanB1+tanAtanB\frac{\tan A-\tan B}{1+\tan A\tan B} โดยA=123°,B=93° A=123\degree,B=93\degree จงหา cot(A−B)\cot\left(A-B\right)1tan(123°−93°)\frac{1}{\tan\left(123\degree-93\degree\right)}1tan(93°−123°)\frac{1}{\tan\left(93\degree-123\degree\right)}cot(93°+123°)\cot\left(93\degree+123\degree\right)cos(93°+123°)\cos\left(93\degree+123\degree\right)
# 4ถูก/ผิดcsc(70°−40°)=1sin(70°−40°)=12\csc\left(70\degree-40\degree\right)=\frac{1}{\sin\left(70\degree-40\degree\right)}=\frac12
# 5เลือกประเภทsinθ=12\sin\theta=\frac12 เมื่อ 0°<θ<π20\degree<\theta<\frac{\pi}{2} จงหาค่า sin3θ\sin3\theta−12-\frac1211−2-2−11-\frac11
# 6เลือกประเภทcosθ=12\cos\theta=\frac12 เมื่อ 0°<θ<π20\degree<\theta<\frac{\pi}{2} จงหาค่า cos3θ\cos3\theta−1-11122\frac{\sqrt2}{2}−22-\frac{\sqrt2}{2}
# 7เลือกประเภทtanθ=1\tan\theta=1 เมื่อ 0°<θ<π20\degree<\theta<\frac{\pi}{2} จงหาค่า cos3θ\cos3\theta11−22-\frac{\sqrt2}{2}13\frac{1}{\sqrt3}−1-1
# 9เลือกประเภทsin75°=x\sin75\degree=xx=sin45°cos30°+cos45°sin30°x=\sin45\degree\cos30\degree+\cos45\degree\sin30\degreex=sin45°cos30°+cos30°sin45°x=\sin45\degree\cos30\degree+\cos30\degree\sin45\degreex=sin45°cos30°−cos45°sin30°x=\sin45\degree\cos30\degree-\cos45\degree\sin30\degreex=sin45°cos30°−cos30°sin45°x=\sin45\degree\cos30\degree-\cos30\degree\sin45\degree
# 10เลือกประเภทcos(60°+30°)=x\cos\left(60\degree+30\degree\right)=xx=sin60°cos30°−cos30°sin60°x=\sin60\degree\cos30\degree-\cos30\degree\sin60\degreex=cos60°cos30°+sin60°sin30°x=\cos60\degree\cos30\degree+\sin60\degree\sin30\degreex=sin60°cos30°−cos60°sin30°x=\sin60\degree\cos30\degree-\cos60\degree\sin30\degreex=cos60°cos30°−sin60°sin30°x=\cos60\degree\cos30\degree-\sin60\degree\sin30\degree
# 11ถูก/ผิดtan105°=tan60°+tan45°1−tan60°tan45°\tan105\degree=\frac{\tan60\degree+\tan45\degree}{1-\tan60\degree\tan45\degree}
# 12ถูก/ผิดtan(180°−45°)=tan180°−tan45°1−tan180°tan45°\tan\left(180\degree-45\degree\right)=\frac{\tan180\degree-\tan45\degree}{1-\tan180\degree\tan45\degree}
# 17เลือกประเภทsin2A=x\sin2A=xx=2cosAsinAx=2\cos A\sin Ax=sin2Acos2Ax=\sin^2A\cos^2Ax=cos2A−sin2Ax=\cos^2A-\sin^2Ax=sin2Acos2Ax=\sin2A\cos2A
# 19เลือกประเภทtan3A=x\tan3A=xx=4tanA−tan3A1−3tan2Ax=\frac{4\tan A-\tan^3A}{1-3^{^{}}\tan^2A}x=4tanA+tan3A1−3tan2Ax=\frac{4\tan A+\tan^3A}{1-3\tan^2A}x=−tan3A+3tanA−3tan2A+1x=\frac{-\tan^3A+3\tan A}{-3\tan^2A+1}x=3tanA+tan3A1−3tan2Ax=\frac{3\tan A+\tan^3A}{1-3\tan^2A}