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Yes. Goblins offers a generous free tier that includes 1 live feedback assignment per week, insights on student mastery and replays, and the ability to upload your own content. The Max plan adds unlimited assignments, superadaptive mode, grade exports, standards growth reports, and SSO/LMS integration, with per-student pricing for schools and districts.

How does Goblins work?

Three simple steps: (1) Share an assignment from thousands of standards-aligned topics using a share code. (2) Students speak and draw their thinking naturally, and Goblins responds with Socratic questioning that sounds just like their teacher. (3) Teachers get real-time formative insights showing what students struggle with and suggestions to inform instruction.

Does Goblins prevent cheating?

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Can I use my own voice with Goblins?

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What math levels does Goblins cover?

Goblins covers math from Grade 5 through AP Calculus, including thousands of standards-aligned topics. Teachers can also upload their own content for custom assignments at any level.

Is Goblins FERPA compliant?

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Does Goblins support English Language Learners?

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What grade level is MA.CF.3.c taught?

This standard is part of the CF curriculum in Virginia Standards of Learning - Mathematics.

Are there practice problems for MA.CF.3.c?

Yes, there are 3 practice problems available for MA.CF.3.c with worked examples.

What learning resources are available for MA.CF.3.c?

There are 5 Khan Academy resources available for MA.CF.3.c, including 3 videos, 2 exercises.

MA.CF.3.c: Prove continuity at a point, using the definition. | SOL

Prove continuity at a point, using the definition.

Example Problems

Let

n(x) = \begin{cases} \ln(-x) & \text{for } x < 0 \\ \ln(x + 1) & \text{for } x \geq 0 \end{cases}

n

continuous at

x = 0

Let

r(x) = \begin{cases} e^x & \text{for } x \leq 0 \\ e^{-x} & \text{for } x > 0 \end{cases}

Is r continuous at

x = 0

Let

h(x) = \begin{cases} e^{2x} & \text{for } x < 0 \\ e^{5x} & \text{for } x \geq 0 \end{cases}

Is h continuous at

x = 0

Khan Academy Resources

Continuity at a point (algebraic)Continuity at a point (graphical)Worked example: point where a function is continuous Functions continuous at specific x-values Continuity at a point

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