# TSI Math: One of These Parabolas Is Not Like the Others

Except for one, all of the following parabolas have the same axis of symmetry. Which one is it?

Intermediate Algebra and Functions | Quadratic and Other Polynomial Expressions, Equations, and Functions |

Mathematics and Statistics Assessment | Quadratic and Other Polynomial Expressions, and Functions |

Product Type | TSI |

TSI | Mathematics and Statistics Assessment TSI Math TSI Mathematics |

TSI Math | Intermediate Algebra and Functions |

TSI Mathematics | Intermediate Algebra and Functions |

Test Prep | TSI |

### Transcript

standard format for problem than the access of symmetry of

a parabola is the vertical line x equals negative b

over two a well assuming this isn't a trick question

in the same math test is no time for paranoia

Three of the four parable is shown here need to

have the same access of symmetry so let's calculate the

acts of symmetry for the first two choices we've got

why equals negative three x squared plus for x minus

five that's a nougat y equal six x squared plus

eight x plus seven seven b and well let's just

see what happens if we get the same result We've

found the access of symmetry common tio three of the

answer choices So check the other answer choices until we

stumble on a different answer Yeah we stumble a lot

around here If we get different results then one of

the first to answer choices is the exception to the

norm And that means one of them's The answer Okay

let's do this thing by the first answer choice has

an x Squared coefficient equal to negative three and an

ex coefficient equal toe four So a here is negative

free and b is for In that case we've got

negative b over two A there So that gets us

negative for over two time thing Free or negative for

negative six or just two thirds Right Well the second

answer choices a is six there and b is eight

right there So it's access of symmetry is the formula

and they're going to be over two way So it's

negative eight over twelve equals negative two thirds And what

does that mean Well since we ended up with a

different result compared to the first choice one of these

is the exception So it's compared to the third answer

choice Well a equals fifteen there and b is negative

Twenty and then we've got a little formula here We

can plug ins We get negative twenty over too Two

times fifteen that's thirty and that's Negative of the negative

twenty over thirty or just positive Two thirds Alright this

result matches the first answer choice So the second answer

choice is our exception The answer is b this guy 00:02:13.97 --> [endTime] right here And that's the answer or not