For , what is the value of the discriminant?
Answer
A. 0
Quick solution
Here , , . So .
FAQ
What does $D = 0$ mean?
means the quadratic equation has two equal real roots.
Very Short Answer practice across CBSE Class 10 Maths Standard chapters.
Answer
A. 0
Quick solution
Here , , . So .
What does $D = 0$ mean?
means the quadratic equation has two equal real roots.
Answer
Quick solution
.
What is prime factorisation?
It expresses a number as a product of prime numbers.
Answer
Irrational
Quick solution
is rational and is irrational. The sum of a non-zero rational number and an irrational number is irrational.
Can a rational number plus an irrational number be rational?
No. The sum is irrational.
Answer
Quick solution
For , sum of zeroes is . Here it is .
What is the sum of zeroes of $ax^2+bx+c$?
It is .
Answer
Quick solution
Put : . Thus , so .
How do you use a known zero to find an unknown coefficient?
Substitute the zero into the polynomial and set the result equal to zero.
Answer
Infinitely many
Quick solution
The second equation is twice the first, so both represent the same line and have infinitely many common points.
When do two linear equations have infinitely many solutions?
When all corresponding coefficients, including constants, are proportional.
Answer
Quick solution
Add the equations: , so . Substituting in gives .
Which method is quick when signs of one variable are opposite?
Adding the equations eliminates that variable.
Answer
and
Quick solution
. Therefore or .
How can a quadratic be solved by factorisation?
Factor it into two linear factors and set each factor equal to zero.
Answer
Quick solution
Subtract consecutive terms: and .
How do you find the common difference of an AP?
Subtract any term from the next term.
Answer
Quick solution
Here , . .
What is the nth-term formula of an AP?
.
Answer
cm
Quick solution
. By BPT, , so . Hence cm.
What does the Basic Proportionality Theorem state?
A line parallel to one side of a triangle divides the other two sides proportionally.
Answer
Quick solution
The ratio is . Divide both terms by to get .
How are corresponding sides of similar triangles related?
Their ratios are equal.
Answer
units
Quick solution
Distance units.
What formula gives the distance between two points?
.
Answer
Quick solution
Midpoint .
What is the midpoint formula?
.
Answer
Quick solution
. Thus , so .
Which identity relates sine and cosine?
.
Answer
Quick solution
The identity applies directly.
What is $\sin^2\theta+\cos^2\theta$ equal to?
It is always .
Answer
m
Quick solution
, so m.
Which trigonometric ratio relates height and shadow?
Tangent equals perpendicular height divided by base distance.
Answer
m
Quick solution
. Thus m.
What is $\tan30^\circ$?
.
Answer
Quick solution
A tangent to a circle is perpendicular to the radius drawn to the point of contact.
How is a tangent related to the radius at the contact point?
They are perpendicular.
Answer
cm
Quick solution
Tangents drawn from the same external point to a circle are equal, so cm.
Are two tangents from the same external point equal?
Yes, their lengths are equal.
Answer
cm
Quick solution
Area cm.
What fraction of a circle is a $90^\circ$ sector?
One-fourth.
Answer
cm
Quick solution
Arc length cm.
What is the arc-length formula?
.
Answer
cm
Quick solution
Cylinder volume . Hemisphere volume . Total cm.
What is the volume of a hemisphere?
.
Answer
cm
Quick solution
Cylinder volume . Cone volume . Total cm.
What is the volume of a cone?
.
Answer
Quick solution
Class mark .
How is class mark calculated?
Add the upper and lower class limits and divide by two.
Answer
Quick solution
Here , so .
Why is $N/2$ used in grouped-data median?
It helps locate the median class through cumulative frequency.
Answer
Quick solution
Prime outcomes are : three favourable outcomes out of six. Probability .
Which prime numbers appear on a die?
and .
Answer
Quick solution
There are balls in total and blue balls. Probability .
What is the basic probability formula?
Probability equals favourable outcomes divided by total equally likely outcomes.