Practice china-kaoyan-math-3 questions with answers and explanations.
f′(x)=3x²+4x. Substituting x=3 gives 39.
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The sum is n(n+1)/2=55, so the mean is 55/10.
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There are 6 favourable outcomes out of 12 equally likely outcomes, so P(red)=6/12.
The coordinate differences are 3 and 4, so the distance is √(3²+4²)=5.
f′(x)=15x²+16x. Substituting x=2 gives 92.
An antiderivative is 2/2 x²+5x. At x=3, the value is 24.0.
The dot product is 2×2+6×4=28.
Rewrite the value using base 3: 27 = 3^3. Matching exponents gives x = 3.
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Use the circle-area formula A = πr². Substituting r = 7 gives A = π × 7² = 49π.
An antiderivative is 1/2 x²+4x. At x=2, the value is 10.0.
The dot product is 1×4+5×3=19.
Rewrite the value using base 2: 4 = 2^2. Matching exponents gives x = 2.
