Let m1, m2 be the slopes of two adjacent sides of a square of side a such that a2 + 11a + 3(m12+m22)=220. If one vertex of the square is (10(cosαsinα),10(sinα+cosα)), where α(0,π2) and the equation of one diagonal is (cosαsinα)x+(sinα+cosα)y=10, then 72(sin4α+cos4α)+a23a+13 is equal to

Option 1 - <p>119&nbsp; &nbsp;</p>
Option 2 - <p>128&nbsp;&nbsp;&nbsp;&nbsp;</p>
Option 3 - <p>145 &nbsp;&nbsp;&nbsp;</p>
Option 4 - <p>155</p>
13 Views|Posted 7 months ago
Asked by Shiksha User
1 Answer
P
7 months ago
Correct Option - 2
Detailed Solution:

m1m2=1, for square a,b,c,d let

A(10(cosαsinα),10(sinα+cosα))

Diagonal : (cosα - sinα)x + (sinα + cosα)y = 10

BD (diagonal)

Dist. Of BD from A is

|10(cosαsinα)2+10(sinα+cosα)210|2=a2

102=a2a=10

Also, a2 + 11a + 3 (m12+m22)=220

210 + 3 (cm12+m22)=220

m12+m22=103

Also, m1 m2 = -1

m21m2=103

or 3,13

m = 3,13

m4103m2+1=0m2=103±100942103±832=3,13

m = ±3,±13

Diagonal AC:

(sinα+cosα)x(cosαsinα)y

=10 cos2α - 10cos2α = 0

Slope of AC = sinα+cosαcosαsinα=tanα+11tanα=tan(α+π4)α=30°

FIGURE

? = 72(116+916)+10030+13=72016+83=128

Thumbs Up IconUpvote Thumbs Down Icon

Similar Questions for you

|r1 – r2| < c1c2 < r1 + r2

-> | 2 4 λ 2 9 | < | 2 λ | < 2 + 4 λ 2 9

| 2 λ | 2 < 4 λ 2 9    

4 λ 2 + 4 8 | λ | < 4 λ 2 9

  λ > 1 3 8 , λ < 1 3 8           

4 λ 2 9 > 0

λ > 3 2 , λ < 3 2

λ ( , 1 3 8 ) ( 1 3 8 , )           

Now,

| 2 4 λ 2 9 | < | 2 λ |            

4 + 4 λ 2 9 4 4 λ 2 9 < 4 λ 2  

4 4 λ 2 9 > 5 λ R  

λ ( , 1 3 8 ) ( 1 3 8 , )  

...Read more

(y – 2) = m (x – 8)

⇒   x-intercept

⇒     ( 2 m + 8 )

⇒   y-intercept

⇒   (–8m + 2)

⇒   OA + OB = 2 m 2  + 8 – 8m + 2

f ' ( m ) = 2 m 2 8 = 0  

-> m 2 = 1 4

-> m = 1 2

-> f ( 1 2 ) = 1 8

->Minimum = 18

...Read more

Taking an Exam? Selecting a College?

Get authentic answers from experts, students and alumni that you won't find anywhere else.

On Shiksha, get access to

66K
Colleges
|
1.2K
Exams
|
6.9L
Reviews
|
1.8M
Answers

Learn more about...

Maths Ncert Solutions class 11th 2026

Maths Ncert Solutions class 11th 2026

View Exam Details

Most viewed information

Summary

Share Your College Life Experience

Didn't find the answer you were looking for?

Search from Shiksha's 1 lakh+ Topics

or

Ask Current Students, Alumni & our Experts

Have a question related to your career & education?

or

See what others like you are asking & answering