JEE doubts
700 doubts found
What does “Product and quotient rules” actually mean in Differentiation, and why does it matter for JEE?
the derivative of a product is u'v+uv'; of a quotient is (u'v−uv')/v².
What does “Methods of integration” actually mean in Integration, and why does it matter for JEE?
substitution, integration by parts, and partial fractions handle most integrals.
What does “Conditional probability” actually mean in Probability, and why does it matter for JEE?
P(A|B) is the probability of A given that B has occurred, equal to P(A∩B)/P(B).
What does “Direction ratios” actually mean in Vectors & 3D Geometry, and why does it matter for JEE?
the components that fix a line's or vector's direction in 3D space.
What does “Matrix as a system solver” actually mean in Matrices & Determinants, and why does it matter for JEE?
a system of linear equations can be written as AX = B, and if A is invertible the unique solution is X = A⁻¹B.
What does “Critical points” actually mean in Application of Derivatives, and why does it matter for JEE?
a point of a function where f′(x)=0 or f′(x) is undefined (including possible endpoints).
I keep getting “Definite integral as area” questions wrong in Applications of Integrals. What's the trap?
treating area below the x-axis as positive.
What does “Order and degree” actually mean in Differential Equations, and why does it matter for JEE?
the order is the highest derivative present; the degree is the power of that highest derivative (once the equation is free of radicals/fractions in derivatives).
I keep getting “Bijective functions” questions wrong in Relations, Functions & Inverse Trigonometry. What's the trap?
trying to invert a function that maps two inputs to the same output.
I keep getting “Inclusion–exclusion” questions wrong in Sets & Statistics. What's the trap?
adding the two group sizes and forgetting to remove the overlap.
I keep getting “Nature of roots” questions wrong in Quadratic Equations. What's the trap?
solving fully when you only need the nature of the roots.
I keep getting “Argand plane” questions wrong in Complex Numbers. What's the trap?
plotting the imaginary part on the x-axis.
I keep getting “Infinite geometric series” questions wrong in Sequences & Series. What's the trap?
applying the sum formula when |r| ≥ 1.
I keep getting “Fundamental principle of counting” questions wrong in Permutations & Combinations. What's the trap?
adding when you should multiply independent choices.
I keep getting “Middle term” questions wrong in Binomial Theorem. What's the trap?
assuming there's always exactly one middle term.
I keep getting “Range of sine and cosine” questions wrong in Trigonometry. What's the trap?
accepting an answer where sinθ > 1.
I keep getting “Equation forms” questions wrong in Straight Lines. What's the trap?
picking a form that doesn't match the given data.
I keep getting “Standard equations” questions wrong in Conic Sections. What's the trap?
mismatching the axis of the parabola with its equation.
I keep getting “Standard limit” questions wrong in Limits & Continuity. What's the trap?
evaluating it as 0/0 and stopping.
I keep getting “Product and quotient rules” questions wrong in Differentiation. What's the trap?
differentiating a product as just u'v'.
I keep getting “Methods of integration” questions wrong in Integration. What's the trap?
reaching for by-parts when a simple substitution works.
I keep getting “Conditional probability” questions wrong in Probability. What's the trap?
assuming P(A|B) equals P(B|A).
I keep getting “Direction ratios” questions wrong in Vectors & 3D Geometry. What's the trap?
confusing direction ratios with direction cosines (which are normalised).
I keep getting “Matrix as a system solver” questions wrong in Matrices & Determinants. What's the trap?
trying to 'divide' by a matrix instead of multiplying by its inverse.