JEE mathematics

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Question
CBSEENMA11015502

The equation esinx-e-sinx -4 = 0 has

  • infinite number of real roots

  • No real root

  • exactly one real root

  • exactly four real roots

Solution

B.

No real root

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Sponsor Area

Question
CBSEENMA12036004

Statement 1: The sum of the series 1 + (1 + 2 + 4) + (4 + 6 + 9) + (9 + 12 + 16) + ...... + (361 + 380 +400) is 8000.
Statement 2: sum from straight k space equals 1 to straight n equals space 1 of left square bracket straight k cubed minus left parenthesis straight k minus 1 cubed right parenthesis right square bracket space equals space straight n cubed, for any natural number n.

  • Statement 1 is false, statement 2 is true

  • Statement 1 is true, statement 2 is true; statement 2 is a correct explanation for statement 1

  • Statement 1 is true, statement 2 is true; statement 2 is not a correct explanation for statement 1

  • Statement 1 is true, statement 2 is false

Solution

B.

Statement 1 is true, statement 2 is true; statement 2 is a correct explanation for statement 1

Statement 1 has 20 terms whose sum is 8000 And statement 2 is true and supporting statement 1.
 kth bracket is (k – 1)2 + k(k – 1) + k2 = 3k2 – 3k + 1.

Question
CBSEENMA11015503

The negation of the statement “If I become a teacher, then I will open a school” is

  • I will become a teacher and I will not open a school

  • Either I will not become a teacher or I will not open a school

  • Neither I will become a teacher nor I will open a school

  • I will not become a teacher or I will open a school

Solution

A.

I will become a teacher and I will not open a school

Let us assume that
p: I become a teacher' and 
q: I will open a school
Then, we can easily as certain that
Negation of (p →q)
~(~p ∨ q) = p ∧ ~q
Which means that ' l' will become a teacher and I will not open a school.

Question
CBSEENMA11015504

Statement I An equation of a common tangent to the parabola straight y squared space equals space 16 space square root of 3 straight x end root and the ellipse 2x2 +y2 =4 is space straight y space equals 2 straight x space plus 2 square root of 3.
Statement II If the line straight Y space equals space mx space plus fraction numerator 4 square root of 3 over denominator straight m end fraction comma space left parenthesis straight m space not equal to 0 right parenthesis is a common tangent to the parabola straight y squared space equals space 16 space square root of 3 straight x and the ellipse 2x2 +y2 =4, then m satisfies m4 +2m2 =24

  • Statement 1 is false, statement 2 is true

  • Statement 1 is true, statement 2 is true; statement 2 is a correct explanation for statement 1

  • Statement 1 is true, statement 2 is true; statement 2 is not a correct explanation for statement 1

  • Statement 1 is true, statement 2 is false

Solution

C.

Statement 1 is true, statement 2 is true; statement 2 is not a correct explanation for statement 1

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Question
CBSEENMA11015505

If n is a positive integer, then open parentheses square root of 3 plus 1 close parentheses to the power of 2 straight n end exponent minus space left parenthesis square root of 3 minus 1 right parenthesis to the power of 2 straight n end exponent space is

  • an irrational number

  • an odd positive integer

  • an even positive integer

  • a rational number other than positive integers

Solution

A.

an irrational number

WiredFaculty
Adding both the binomial expansions above, we get
WiredFaculty
It is the irrational number because of odd power of square root of 3 appears in each of the terms.