Dedikerad kubisk ekvationslösare med verkliga och komplexa rötter, Cardano-metodsteg, kubikgrafer och utarbetade exempel.
Kalkylator för återstoden av teorem
Ange dina polynomkoefficienter ovan och klicka på "Utvärdera f(c)" för att se resultat.The Remainder Theorem states that when a polynomial f(x) is divided by a linear divisor (x − c), the remainder is exactly f(c). This means you can evaluate any polynomial at any point simply by performing synthetic division — the last number in the bottom row equals f(c).
The Factor Theorem is a direct corollary: if f(c) = 0, then (x − c) is a factor of f(x). These two theorems together provide a powerful bridge between evaluation and factoring. Instead of plugging in values manually (which involves large exponents), synthetic division gives the same answer with simpler arithmetic.
For cubic equations, the Remainder Theorem is especially useful for root verification. After finding candidate roots via the Rational Root Theorem, you can quickly confirm which ones are actual roots by checking whether f(c) = 0. This is faster and less error-prone than direct substitution, particularly for large coefficients.
Evaluate f(c) for any value c without computing large powers directly — synthetic division handles it cleanly.
After finding candidate roots, the Remainder Theorem instantly confirms which candidates are actual roots.
The theorem beautifully connects the concepts of division, evaluation, and factoring into one unified framework.
When dividing by (x+3), the evaluation point is c = −3, not c = 3. The theorem uses (x MINUS c).
The Remainder Theorem is not limited to cubics. It works for polynomials of any degree.
The remainder from division equals f(c). Don't confuse the quotient (a polynomial) with the remainder (a number).
| Theorem | f(x) ÷ (x−c) has remainder f(c) |
| Factor Test | f(c) = 0 means (x−c) is a factor |
| Method | Use synthetic division for efficiency |
| Works For | Polynomials of any degree |
| Key Benefit | Avoids computing large powers directly |
Syntetisk division ger dig den kvarvarande kvoten kvadratisk *och* resten. Detta verktyg förbigår kvoten och ger dig bara resten.
Ja! Resten<span class="font-mono text-primary-700 bg-primary-50 px-1 rounded">R</span>är bokstavligen<span class="font-mono text-primary-700 bg-primary-50 px-1 rounded">y</span>-koordinat på grafen när<span class="font-mono text-primary-700 bg-primary-50 px-1 rounded">x = c</span>.
Grattis! Du har hittat roten till ekvationen genom faktorsatsen.
Faktorsatsen är ett specialfall av Remainder Theorem. Om resten f(c) = 0, så är (x - c) en faktor av polynomet.
Ja, Remainder Theorem fungerar för polynom av vilken grad som helst, inte bara kubik. Det är ett universellt verktyg för att utvärdera polynomvärden.
