Practice China questions with answers and explanations.
By Vieta’s formula, the sum of the roots equals the coefficient 14.
aₙ=a₁+(n−1)d=10+(7−1)×3=28.
aₙ=a₁+(n−1)d=9+(6−1)×2=19.
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 2 favourable outcomes out of 6 equally likely outcomes, so P(red)=2/6.
The coordinate differences are 3 and 4, so the distance is √(3²+4²)=5.
f′(x)=3x²+12x. Substituting x=2 gives 36.
An antiderivative is 2/2 x²+1x. At x=3, the value is 12.0.
The dot product is 2×3+2×2=10.
Rewrite the value using base 3: 27 = 3^3. Matching exponents gives x = 3.
Percentage=(9/44)×100=20.45.
Subtract 10 from both sides and divide by 6: x = (34-10)/6 = 4.
