Practice Specialization in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Applying a general theorem or formula to a specific case by substituting particular values for the variables or parameters.

What does this general statement say about MY specific situation?

Showing a random 20 of 50 problems.

Example 1

hard
Specialize the derivative product rule (fg)โ€ฒ=fโ€ฒg+fgโ€ฒ(fg)'=f'g+fg' to f(x)=x,g(x)=sinโกxf(x)=x, g(x)=\sin x and write (xsinโกx)โ€ฒ(x\sin x)'.

Example 2

hard
Common mistake check: specializing a2โˆ’b2=(aโˆ’b)(a+b)a^2-b^2=(a-b)(a+b) to a=0a=0 gives what identity? Why does it hold?

Example 3

easy
The area of a rectangle is A=lwA = lw. Specialize to a square of side ss.

Example 4

hard
De Moivre: (cosโกฮธ+isinโกฮธ)n=cosโก(nฮธ)+isinโก(nฮธ)(\cos\theta+i\sin\theta)^n=\cos(n\theta)+i\sin(n\theta). Specialize to ฮธ=60โˆ˜,n=3\theta=60^\circ, n=3 and identify the result.

Example 5

easy
Specialize the identity a2โˆ’b2=(aโˆ’b)(a+b)a^2 - b^2 = (a-b)(a+b) with a=7,b=3a=7, b=3 to compute 72โˆ’327^2 - 3^2.

Example 6

medium
Specialize the matrix-vector product AvA\mathbf v with A=(1234)A=\begin{pmatrix}1&2\\3&4\end{pmatrix} and v=(11)\mathbf v=\begin{pmatrix}1\\1\end{pmatrix}.

Example 7

medium
Specialize Heron's formula A=s(sโˆ’a)(sโˆ’b)(sโˆ’c)A=\sqrt{s(s-a)(s-b)(s-c)} (with s=a+b+c2s=\tfrac{a+b+c}{2}) to a 33-44-55 triangle. Confirm the area.

Example 8

medium
Specialize the cosine double-angle formula cosโก2ฮธ=1โˆ’2sinโก2ฮธ\cos2\theta=1-2\sin^2\theta to ฮธ=30โˆ˜\theta=30^\circ.

Example 9

easy
Specialize the sine sum identity sinโก(A+B)=sinโกAcosโกB+cosโกAsinโกB\sin(A+B)=\sin A\cos B+\cos A\sin B to A=B=45โˆ˜A=B=45^\circ and simplify.

Example 10

challenge
Specialize the derivative power rule and chain rule to differentiate f(x)=(3x)2f(x)=(3x)^2 two ways; confirm they agree.

Example 11

medium
Specialize f(x)=ax2+bx+cf(x)=ax^2+bx+c to find its value at x=0x=0. What does this reveal about cc?

Example 12

easy
The general formula for the sum of a geometric series is Sn=a(rnโˆ’1)rโˆ’1S_n = \frac{a(r^n-1)}{r-1}. Specialise to a=1,r=2a=1, r=2 and compute S5S_5.

Example 13

easy
Specialize (aโˆ’b)2=a2โˆ’2ab+b2(a-b)^2=a^2-2ab+b^2 to expand (xโˆ’4)2(x-4)^2.

Example 14

medium
Specialize the AM-GM inequality a+b2โ‰ฅab\frac{a+b}{2}\ge\sqrt{ab} to a=ba=b. What happens?

Example 15

medium
Specialize the compound-interest formula A=P(1+r)tA=P(1+r)^t to P=100,r=0.1,t=2P=100, r=0.1, t=2.

Example 16

medium
Specialize the geometric series sum a(1โˆ’rn)1โˆ’r\frac{a(1-r^n)}{1-r} to a=1,r=12,n=3a=1,r=\frac12,n=3.

Example 17

medium
Specialize the dot product formula uโ‹…v=u1v1+u2v2+u3v3\mathbf u\cdot\mathbf v=u_1v_1+u_2v_2+u_3v_3 to u=(1,2,3),v=(4,โˆ’1,2)\mathbf u=(1,2,3), \mathbf v=(4,-1,2).

Example 18

medium
Specialize the integral โˆซxnโ€‰dx=xn+1n+1+C\int x^n\,dx=\dfrac{x^{n+1}}{n+1}+C (for nโ‰ โˆ’1n\ne -1) to n=4n=4.

Example 19

medium
Specialize the identity sinโก(2ฮธ)=2sinโกฮธcosโกฮธ\sin(2\theta)=2\sin\theta\cos\theta to ฮธ=45โˆ˜\theta=45^\circ.

Example 20

hard
Specialize the quadratic formula to a=2,b=4,c=โˆ’30a=2, b=4, c=-30 and find the roots.