Practice china-kaoyan-math-3 questions with answers and explanations.
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.
Subtract 6 from both sides and divide by 5: x = (11-6)/5 = 1.
By Vieta’s formula, the sum of the roots equals the coefficient 13.
aₙ=a₁+(n−1)d=5+(11−1)×1=15.
Choose an option to check your answer.
The sum is n(n+1)/2=28, so the mean is 28/7.
Choose an option to check your answer.
There are 3 favourable outcomes out of 6 equally likely outcomes, so P(red)=3/6.
The coordinate differences are 3 and 4, so the distance is √(3²+4²)=5.
f′(x)=6x²+10x. Substituting x=3 gives 84.
An antiderivative is 3/2 x²+2x. At x=4, the value is 32.0.
The dot product is 3×2+3×1=9.
