← Back to topics

Mathematics · Topic 1

Vectors

Sub-topic 1 2025 · National One-Eighth Free

Scalar product of $\mathbf{a}+\mathbf{b}$ and $\mathbf{a}-\mathbf{b}$ using $|\mathbf{a}|^2-|\mathbf{b}|^2$

Read past contest →
Sub-topic 2 2025 · National One-Eighth Premium

$(a+b)\cdot(a-b)$ for $a=2i+3j$ and $b=4i-3j$

Read past contest →
Sub-topic 3 2024 · National Preliminary Premium

Meaning of $\mathbf{a}\cdot\mathbf{b}=0$ for non-zero vectors (true/false)

Read past contest →
Sub-topic 4 2024 · National Preliminary Premium

Vector of length $65$ in the direction of $5\mathbf{i}-12\mathbf{j}$

Read past contest →
Sub-topic 5 2026 · National Preliminary Premium

Sine of the angle between $2\mathbf{i}+\mathbf{j}$ and $\mathbf{i}-\mathbf{j}$

Read past contest →
Sub-topic 6 2025 · National Preliminary Premium

Sine of the angle between $2\mathbf{i}+3\mathbf{j}$ and $3\mathbf{i}+2\mathbf{j}$

Read past contest →
Sub-topic 7 2026 · National Preliminary Premium

Sine of the angle between $2\mathbf{i}+\mathbf{j}$ and $\mathbf{i}-\mathbf{j}$ (formula method)

Read past contest →
Sub-topic 8 2026 · National Preliminary Premium

Component of $5\mathbf{i}+6\mathbf{j}$ in the direction of $3\mathbf{i}+4\mathbf{j}$

Read past contest →
Sub-topic 9 2026 · National Preliminary Premium

Tangent of the angle between $2\mathbf{i}+\mathbf{j}$ and $\mathbf{i}+2\mathbf{j}$

Read past contest →
Sub-topic 10 2026 · National Quarterfinal Premium

Locus of $p(x,y)$ when $2x\mathbf{i}+y\mathbf{j}$ and $x\mathbf{i}-2y\mathbf{j}$ are perpendicular

Read past contest →
Sub-topic 11 2026 · National Quarterfinal Premium

Tangent of the angle between $5\mathbf{i}+\mathbf{j}$ and $5\mathbf{i}-\mathbf{j}$

Read past contest →
Sub-topic 12 2026 · National One-Eighth Premium

Locus of $p(x,y)$ when $2x\mathbf{i}+y\mathbf{j}$ and $x\mathbf{i}-2y\mathbf{j}$ are perpendicular (speed race)

Read past contest →
Sub-topic 13 2018 · National One-Eighth Premium

Value of $x$ when $|x\mathbf{i}+7\mathbf{j}|=25$

Read past contest →
Sub-topic 14 2025 · National Quarterfinal Premium

Sine of the angle between $3\mathbf{i}+\mathbf{j}$ and $\mathbf{i}-2\mathbf{j}$

Read past contest →
Sub-topic 15 2025 · National Quarterfinal Premium

Tangent of the angle between $4\mathbf{i}+2\mathbf{j}$ and $2\mathbf{i}+4\mathbf{j}$

Read past contest →
Sub-topic 16 2023 · National One-Eighth Premium

Vector of magnitude $10$ in the direction of $\mathbf{i}+\sqrt{3}\mathbf{j}$

Read past contest →
Sub-topic 17 2021 · National One-Eighth Premium

Magnitudes of $2a-b$, $3a+3b$, $a+2b$ for $a=2i+j$, $b=i-3j$

Read past contest →
Sub-topic 18 2024 · National One-Eighth Premium

Magnitude of $3\mathbf{a}+2\mathbf{b}$ for $\mathbf{a}=3\mathbf{i}-2\mathbf{j}$, $\mathbf{b}=2\mathbf{i}+3\mathbf{j}$

Read past contest →
Sub-topic 19 2024 · Regional Championship Premium

Vector from $a(-3,2)$ to $b(2,-6)$ in terms of $\mathbf{i}$ and $\mathbf{j}$

Read past contest →
Sub-topic 20 2025 · National Preliminary Premium

Value of $k$ making $2\mathbf{a}+k\mathbf{b}$ or $k\mathbf{a}+2\mathbf{b}$ parallel to $\mathbf{i}$ or $\mathbf{j}$

Read past contest →
Sub-topic 21 2024 · National Preliminary Premium

What $\mathbf{a}\cdot\mathbf{b}=0$ implies about two vectors (true/false)

Read past contest →
Sub-topic 22 2013 · National Preliminary Premium

Properties of vectors and the scalar product (true/false)

Read past contest →
Sub-topic 23 2013 · National Preliminary Premium

Vector of length $10$ parallel to $2\mathbf{i}-2\mathbf{j}$

Read past contest →
Sub-topic 24 2013 · National Preliminary Premium

Vector of length $10$ perpendicular to $3\mathbf{i}+4\mathbf{j}$

Read past contest →
Sub-topic 25 2013 · National Preliminary Premium

Scalar product of $5\mathbf{i}-7\mathbf{j}$ and $14\mathbf{i}+10\mathbf{j}$

Read past contest →
Sub-topic 26 2021 · National Preliminary Premium

Value of $k$ for which $3\mathbf{i}-k\mathbf{j}$ and $12\mathbf{i}+k\mathbf{j}$ are perpendicular

Read past contest →
Sub-topic 27 2021 · National Preliminary Premium

Velocity from the position vector $\mathbf{r}=at^2\mathbf{i}+bt\mathbf{j}$

Read past contest →
Sub-topic 28 2021 · National Preliminary Premium

Value of $x$ when $|5\mathbf{i}+x\mathbf{j}|=13$

Read past contest →
Sub-topic 29 2021 · National Quarterfinal Premium

Cosine of the angle between $12\mathbf{i}-5\mathbf{j}$ and $4\mathbf{i}+3\mathbf{j}$

Read past contest →
Sub-topic 30 2021 · National Quarterfinal Premium

Bearing of the direction of the vector $\mathbf{i}-\mathbf{j}$

Read past contest →
Sub-topic 31 2023 · National One-Eighth Premium

Final velocity $\mathbf{v}=\mathbf{u}+\mathbf{a}t$ (three examples)

Read past contest →
Sub-topic 32 2023 · National Quarterfinal Premium

Angular momentum $\mathbf{l}=\mathbf{r}\times m\mathbf{v}$ of a $3$ kg particle

Read past contest →
Sub-topic 33 2023 · National Quarterfinal Premium

Vector of magnitude $10$ in the direction of $\mathbf{i}+\sqrt{3}\mathbf{j}$ (second copy)

Read past contest →