Change the subject of an equation
Changing the Subject
Changing the Subject
No. You can't drop math as a subject but you can learn how to change the subject of an equation. The subject of an equation is usually what we are trying to solve for.
No. You can't drop math as a subject but you can learn how to change the subject of an equation. The subject of an equation is usually what we are trying to solve for.
In order to be the subject, the variable needs to satisfy two conditions:
In order to be the subject, the variable needs to satisfy two conditions:
- It is alone by itself on the left side of the equation.
- There is no duplicate of that variable on the right side.
Example
Example
In physics, we learn that the final velocity, v, is equals to the initial velocity, u, plus the product of a constant acceleration, a, with time travelled, t. i.e. v = u + at.
In physics, we learn that the final velocity, v, is equals to the initial velocity, u, plus the product of a constant acceleration, a, with time travelled, t. i.e. v = u + at.
This formula is useful to find the final velocity but sometimes we want to find the initial velocity instead so we can make u the subject. Other times, we might want a or t as the subject.
This formula is useful to find the final velocity but sometimes we want to find the initial velocity instead so we can make u the subject. Other times, we might want a or t as the subject.
Test Yourself (Level 1)
Test Yourself (Level 1)
Use the applet below to test your ability to change the subject of an equation.
Use the applet below to test your ability to change the subject of an equation.