Practice China questions with answers and explanations.
The coordinate differences are 3 and 4, so the distance is √(3²+4²)=5.
f′(x)=15x²+4x. Substituting x=3 gives 147.
The coordinate differences are 3 and 4, so the distance is √(3²+4²)=5.
f′(x)=12x²+16x. Substituting x=2 gives 80.
An antiderivative is 2/2 x²+4x. At x=3, the value is 21.0.
The dot product is 2×3+5×2=16.
Rewrite the value using base 3: 27 = 3^3. Matching exponents gives x = 3.
Choose an option to check your answer.
Use the circle-area formula A = πr². Substituting r = 7 gives A = π × 7² = 49π.
Percentage=(8/33)×100=24.24.
Subtract 8 from both sides and divide by 2: x = (16-8)/2 = 4.
By Vieta’s formula, the sum of the roots equals the coefficient 12.
Choose an option to check your answer.
The sum is n(n+1)/2=55, so the mean is 55/10.
