PSAT 8/9 flashcards
PSAT 8/9 · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Main idea
- The central point a passage develops as a whole. The correct answer must cover the entire text rather than a single supporting detail or an overly broad topic.
- Supporting detail
- A specific fact, example, or statistic that backs up a passage's main claim. Detail questions ask what the text states, not what it implies.
- Inference
- A conclusion that follows logically from stated information but is not directly stated. Correct inferences require only a small, well-supported step beyond the text.
- Words in context
- A question type asking which word best fits a sentence's meaning. Test each option by substituting it and checking meaning, tone, and register against surrounding clues.
- Transition words
- Connectors signaling relationships between ideas: contrast (however, although), cause (therefore, because), addition (moreover, also), and example (for instance).
- Comma splice
- An error joining two independent clauses with only a comma. Fix it with a period, semicolon, colon, or a comma plus a coordinating conjunction.
- Independent clause
- A group of words with a subject and a working verb that expresses a complete thought and can stand alone as a sentence.
- Nonessential clause
- Extra information set off by paired commas, dashes, or parentheses. It can be removed without changing the sentence's core grammar or meaning.
- Subject-verb agreement
- The rule that a verb must match its subject in number. Ignore prepositional phrases and parenthetical insertions when identifying the true subject.
- Pronoun-antecedent agreement
- A pronoun must match its antecedent in number and person. Singular antecedents like 'each' or 'everyone' take singular pronouns such as 'its'.
- Colon use
- A colon introduces a list, explanation, or example and must follow a complete independent clause, never a sentence fragment or a verb phrase.
- Semicolon use
- A semicolon joins two closely related independent clauses without a conjunction, or separates items in a list that already contain commas.
- Quantitative evidence
- Data in a table or graph used to support a claim. The correct choice must match the data's direction and compare the right groups.
- Tone and purpose
- A question type asking why an author writes or how the author feels. Answer using the passage's overall attitude, not a single vivid word.
- Linear equation
- An equation of the form y = mx + b, where m is the constant rate of change (slope) and b is the initial value (y-intercept).
- Slope formula
- The slope between two points equals the change in y divided by the change in x: m = (y2 - y1)/(x2 - x1).
- Parallel lines
- Two lines in the same plane that never intersect. They have equal slopes but different y-intercepts, so their system has no solution.
- Perpendicular lines
- Lines that meet at a right angle. Their slopes are negative reciprocals, so the product of the slopes equals -1.
- Quadratic formula
- For ax^2 + bx + c = 0, the solutions are x = (-b +/- sqrt(b^2 - 4ac))/(2a). It solves any quadratic equation.
- Discriminant
- The expression b^2 - 4ac in the quadratic formula. Positive gives two real solutions, zero gives one, and negative gives none.
- Exponent product rule
- When multiplying powers with the same base, add the exponents: x^a * x^b = x^(a+b). This rule applies only to matching bases.
- Exponent power rule
- When raising a power to a power, multiply the exponents: (x^a)^b = x^(ab). Apply it to every factor inside the parentheses.
- Percent change
- The ratio of the change to the original amount, times 100: (new - old)/old * 100. A positive result is an increase.
- Proportion
- An equation stating two ratios are equal, such as a/b = c/d. Solve by cross-multiplying to get ad = bc.
- Circle area
- The area enclosed by a circle equals pi times the radius squared: A = pi*r^2. The radius is half the diameter.
- Circumference
- The distance around a circle, equal to 2*pi*r or pi*d, where r is the radius and d is the diameter.
- Pythagorean theorem
- In a right triangle, the square of the hypotenuse equals the sum of the squares of the legs: a^2 + b^2 = c^2.
- Mean
- The arithmetic average of a data set, found by adding all values and dividing by the number of values. It is sensitive to outliers.
- Median
- The middle value of an ordered data set, or the average of the two middle values when the count is even. It resists outliers.
- Range
- A measure of spread equal to the largest value minus the smallest value in a data set. Adding a constant to all values leaves it unchanged.
- Function notation
- The notation f(x) names a function's output for input x. If f(3) = 7, then the point (3, 7) lies on the graph.
- System of equations
- Two or more equations solved together. The solution is the point satisfying all equations, found by substitution or elimination.