Practice China questions with answers and explanations.
aₙ=a₁+(n−1)d=7+(13−1)×3=43.
f′(x)=9x²+12x. Substituting x=4 gives 192.
An antiderivative is 4/2 x²+3x. At x=5, the value is 65.0.
The dot product is 4×3+4×2=20.
Rewrite the value using base 5: 3125 = 5^5. Matching exponents gives x = 5.
Choose an option to check your answer.
Use the circle-area formula A = πr². Substituting r = 5 gives A = π × 5² = 25π.
Percentage=(11/26)×100=42.31.
Subtract 7 from both sides and divide by 6: x = (19-7)/6 = 2.
By Vieta’s formula, the sum of the roots equals the coefficient 16.
aₙ=a₁+(n−1)d=6+(12−1)×2=28.
Choose an option to check your answer.
The sum is n(n+1)/2=36, so the mean is 36/8.
Choose an option to check your answer.
There are 4 favourable outcomes out of 8 equally likely outcomes, so P(red)=4/8.
