Vault Of Euclid

Today's setSaturday, 8 August 2026

10 problems across Real & complex analysis, Calculus and Linear algebra.

23
Days
230
Problems served
1 core Series of numbers Real & complex analysis
If \( \mathbf{B} \times \mathbf{C} = \mathbf{0} \), what can be concluded about \( \mathbf{B} \) and \( \mathbf{C} \)?
cross-productvectorsparallel-vectorslinear-dependencezero-vectormagnitudeangle-between-vectorsmultivariable-calculusanalytic-geometryvector-algebra

Sign in to see the solution and its full explanation.

2 hard Antiderivatives Calculus
Find \( \int \tan^2 \theta \sec^4 \theta \, d\theta \).
calculus-icalculus-iiindefinite-integraltrigonometric-integralsintegration-by-substitutiontangentsecantpythagorean-identitypower-ruleantiderivativesevaluate-integral

Sign in to see the solution and its full explanation.

3 hard The definite integral Calculus
Find \( \lim_{h \to 0} \frac{1}{h} \int_{2}^{2+h} \sqrt{t^{2}+2} \, dt \).
calculus-idefinite-integrallimitderivative-definitionfundamental-theorem-of-calculusevaluate-limitdifference-quotientintegration

Sign in to see the solution and its full explanation.

4 warmup Limits Calculus
Evaluate the limit: \[ \lim_{x\to 1} \frac{x^{4}-1}{x-1} \]
calculus-ilimitsl-hopitalindeterminate-formsderivativespower-ruleevaluate-limitrational-functiondirect-substitutionalgebraic-limitlimit-evaluationzero-over-zero

Sign in to see the solution and its full explanation.

5 core Multiple integrals Calculus
Consider the region in the first quadrant between the functions \(y = 2x\) and \(y = x^2\). Describe the region first as Type I and then as Type II.
multiple-integralsdouble-integralsregion-of-integrationtype-i-regiontype-ii-regionchange-of-order-of-integrationmultivariable-calculuscalculus-iiiinequalitiesfunctions-and-graphsintersection-of-curvesset-builder-notation

Sign in to see the solution and its full explanation.

6 warmup Multivariable calculus Calculus
Parameterize the surface $z = x^2 + 2y^2$ over the circular region $R$ enclosed by the circle of radius 2 that is centered at the origin.
surface-parameterizationparametric-equationsmultivariable-calculuspolar-coordinatescircular-regionparaboloidvector-valued-functionsdomain-mapping

Sign in to see the solution and its full explanation.

7 warmup Parametric equations and vector functions Calculus
Solve \( \frac{dy}{dx} = ky \).
differential-equationsseparable-differential-equationsexponential-growthexponential-decayintegrationnatural-logarithmabsolute-valuearbitrary-constantcalculus-icalculus-iifind-general-solutionfirst-order-differential-equation

Sign in to see the solution and its full explanation.

8 core Logarithmic and exponential functions Calculus
Prove that the only solutions of the differential equation \(f'(x) = f(x)\) are the functions \(Ce^x\), where \(C\) is a constant.
differential-equationsexponential-functionproduct-ruleuniqueness-of-solutioncalculus-ifirst-order-linearconstant-of-integrationprove-uniqueness

Sign in to see the solution and its full explanation.

9 core Determinants Linear algebra
Solve the system using determinants \begin{cases} x + y + z = 5 \\ x-2y-3z = -1 \\ 2x + y - z = 3 \end{cases}

Sign in to see the solution.

10 warmup Vector spaces Linear algebra
Find the measure of the angle between planes \( x+y-z=3 \) and \( 3x-y+3z=5 \). Give the answer in radians and round to two decimal places.
analytic-geometryangle-between-planesarccoscalculus-iiidot-productfind-anglemultivariable-calculusnormal-vectorsplanesradiansvector-magnitudevectors

Sign in to see the solution and its full explanation.