मराठी
तामिळनाडू बोर्ड ऑफ सेकेंडरी एज्युकेशनएचएससी विज्ञान इयत्ता ११

If cos 2θ = 0, determine [θcosθsinθcosθsinθ0sinθ0cosθ]2 - Mathematics

Advertisements
Advertisements

प्रश्न

If cos 2θ = 0, determine  `[(theta, costheta, sintheta),(costheta, sintheta, 0),(sintheta, 0, costheta)]^2`

बेरीज
Advertisements

उत्तर

Given cos 2θ = 0

Let A = `[(theta, costheta, sintheta),(costheta, sintheta, 0),(sintheta, 0, costheta)]^2`

A = `[|(sintheta, 0),(0, costheta)| - cos|(costheta, 0),(sintheta, costheta)| + sintheta|(costheta, sintheta),(sintheta, 0)|]^2`

A = `[0 - cos theta(costheta - 0) + sintheta(0 - sin^2theta)]^2`

A = `[- cos3theta - sintheta]2`

A = `[cos^3theta + sin^3theta]^2`  .......(1)

cos 2θ = 0

⇒ 2θ = `pi/2`

⇒ θ = `pi/4`

Substituting θ = `pi/4` in equation (1) we get

A = `[cos^3pi/4 + sin^3 pi/4]^2`

= `[(1/sqrt(2))^3 + (1/sqrt(2))^3]^2`

= `[2 xx (1/sqrt(2))^3]^2`

= `[2 xx 1/(2sqrt(2))]^2`

=`[1/sqrt(2)]^2`

A = `1/2`

shaalaa.com
Determinants
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 7: Matrices and Determinants - Exercise 7.4 [पृष्ठ ४०]

APPEARS IN

सामाचीर कलवी Mathematics - Volume 1 and 2 [English] Class 11 TN Board
पाठ 7 Matrices and Determinants
Exercise 7.4 | Q 5 | पृष्ठ ४०

संबंधित प्रश्‍न

Show that `|(x + 2"a", y + 2"b", z + 2"c"),(x, y, z),("a", "b", "c")|` = 0


Find the value of `|(1, log_x y, log_x z),(log_y x, 1, log_y z),(log_z x, log_z y, 1)|` if x, y, z ≠ 1


If A = `[(1/2, alpha),(0, 1/2)]`, prove that `sum_("k" = 1)^"n" det("A"^"k") = 1/3(1 - 1/4)` 


If λ = – 2, determine the value of `|(0, lambda, 1),(lambda^2, 0, 3lambda^2 + 1),(-1, 6lambda - 1, 0)|`


Solve the following problems by using Factor Theorem:

Show that `|(x, "a", "a"),("a", x, "a"),("a", "a", x)|` = (x – a)2 (x + 2a)


Solve that `|(x + "a", "b", "c"),("a", x + "b", "c"),("a", "b", x + "c")|` = 0


Show that `|("b" + "C", "a", "a"^2),("c" + "a", "b", "b"^2),("a" + "b", "c", "c"^2)|` = (a + b + c)(a – b)(b – c)(c – a)


Show that `|(1, 1, 1),(x, y, z),(x^2, y^2, z^2)|` = (x – y)(y – z)(z – x)


Find the area of the triangle whose vertices are (0, 0), (1, 2) and (4, 3)


Determine the values of a and b so that the following matrices are singular:

B = `[("b" - 1, 2, 3),(3, 1, 2),(1, -2, 4)]`


Choose the correct alternative:
The value of x, for which the matrix A = `[("e"^(x - 2), "e"^(7 + x)),("e"^(2 + x), "e"^(2x + 3))]` is singular


Choose the correct alternative:
If A = `|(-1, 2, 4),(3, 1, 0),(-2, 4, 2)|` and B = `|(-2, 4, 2),(6, 2, 0),(-2, 4, 8)|`, then B is given by


The remainder obtained when 1! + 2! + 3! + ......... + 10! is divided by 6 is,


If Δ is the area and 2s the sum of three sides of a triangle, then


If f(x) = `|(cos^2x, cosx.sinx, -sinx),(cosx sinx, sin^2x, cosx),(sinx, -cosx, 0)|`, then for all x


Find the area of the triangle with vertices at the point given is (1, 0), (6, 0), (4, 3).


Choose the correct option:

Let `|(0, sin theta, 1),(-sintheta, 1, sin theta),(1, -sin theta, 1 - a)|` where 0 ≤ θ ≤ 2n, then


Let a, b, c, d be in arithmetic progression with common difference λ. If `|(x + a - c, x + b, x + a),(x - 1, x + c, x + b),(x - b + d, x + d, x + c)|` = 2, then value of λ2 is equal to ______.


`|("b" + "c", "c", "b"),("c", "c" + "a", "a"),("b", "a", "a" + "b")|` = ______.


If `x∈R|(8, 2, x),(2, x, 8),(x, 8, 2)|` = 0, then `|x/2|` is equal to ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×