Find the best tutors and institutes for Class 10 Tuition

Find Best Class 10 Tuition

Please select a Category.

Please select a Locality.

No matching category found.

No matching Locality found.

Outside India?

Search for topics

Consider ?ACB, right-angled at C, in which AB = 29 units, BC = 21 units and ?ABC = ?. Determine the values of i. cos 2? + sin2?, ii. cos2? – sin2?.

Asked by Last Modified  

CBSE/Class 10/Mathematics Tuition/Class IX-X Tuition

Follow 14
Answer

11 Answers

Please enter your answer

Chemistry Teacher

For right angle triangle use pythagorous theorem (AC)^2 = (AB)^2 + (BC)2 PUT value of all find answer
Comments

Right triangle 1 1.034 2 0.964
Comments

Tutor

41/29 and1/29
Comments

Maths Magic

1) 41/29. 2) 1/29.
Comments

Tutor

1, sqrt(41/841)
Comments

Science Teacher

first find the value of AC by Pythagoras theorem then use the formula for cos2x and sin2x
Comments

Use Pythagoras theorem 29sq-21sq= xsq X=20 Area= 21*10=210
Comments

Math Magician

In triangle ACB, angle ACB is right angle, AB = 29 unit, it is hypotenuse, BC = 21unit, So, AC2= hypotenuse2- BC2= AB2 - BC2= 292 – 212= 202 or AC = 20 unit. angle ABC = angle β. sin β = AC/AB = 20/29 and cos β= BC/AB = 21/29 …now Question 1: Sin2 β +cos2 β... read more

In triangle ACB, angle ACB is right angle, AB = 29 unit, it is hypotenuse, BC = 21unit,

So, AC2= hypotenuse2-  BC2= AB2 - BC2= 292 – 212= 202   or AC = 20 unit. angle ABC = angle β.

sin β = AC/AB  = 20/29 and  cos β= BC/AB = 21/29  …now 

Question 1:

Sin2 β +cos2 β = (20/29)2  + (21/29)2  = 202 /292    + 212 /292 = 841/841 = 1 answer.

Question 2:

cos2 β – sin2 β = (21/29)2 –( 20/29)2 =  41/ 292 = 41/841 = .048 answer.

read less
Comments

Tutor

In ACB, we have AC = (AB2 BC2) = = (8)(50) = 400 = 20 units So, sin = AC/AB = 20/29, cos = BC/AB = 21/29. Now, (i) cos2 + sin2 = (29/21)2 + 21/292 = (202 + 212)/292 = (400 + 441)/841 = 1, and (ii) cos2 -- sin2 = (29/21)2 -- 21/292 = / 292 = 41/841 read more
In Δ ACB, we have AC = √(AB2 − BC2) = √[(29)2 − (21) 2) = √[(29 − 21)(29 + 21)] = √(8)(50) = √400 = 20 units So, sin θ = AC/AB = 20/29, cos θ = BC/AB = 21/29. Now, (i) cos2θ + sin2θ = (29/21)2 + 21/292 = (202 + 212)/292 = (400 + 441)/841 = 1, and (ii) cos2θ – sin2θ = (29/21)2 – 21/292 = [(21 + 20)(21 – 20)] / 292 = 41/841 read less
Comments

Learn Science from the Scientist

Using Pythagoras’s theorem; Third side = (29^2-21^2)^(1/2)=20 Now angle B=Cos^-1 (20/21) I assume next part asks cos^2B+Sin^2B, this will be 1 irrespective of what is B Second with - sign this equals to cos 2B or 2cos^2(B)-1 Just put cos B value here and get the result. read more

Using Pythagoras’s theorem;

Third side = (29^2-21^2)^(1/2)=20

Now angle B=Cos^-1 (20/21)

I assume next part asks cos^2B+Sin^2B, this will be 1 irrespective of what is B

Second with - sign this equals to cos 2B or 2cos^2(B)-1

Just put cos B value here and get the result.

read less
Comments

View 9 more Answers

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Related Lessons

Equation of the median of a triangle with coordinates A ( 5 -4 ) , B (2 , 5 ) and C (4 ,-1 ) passing through vertex A.
Median from vertex A bisects the opposite side B C. Let D be the mid point of BC. Coordinates of D ( 3 , 2) Using two point formula of straight line, we can find the equation of the median. A (5 ,-4...

B.Sudhakar | 16 Mar

2 0
0

Basics question for today
Can u tell why factorial 0 and factorial 1 has same value as 1?

Vikas K. | 20 Feb

0 0
0

Tips To Score Excellent Marks In Maths
Hello students. Some tips for you all to score excellent marks in Maths: (1) Do not mug up sums and Theorems. Try to understand the concept. (2) Memorise all formulas and identities well. (3) Understand...

Deval T. | 08 Jan

0 0
0

Recommended Articles

Board exams are an integral part of a student s life. It prepares them for the future and strengthens their observation. Besides, boards exams also teach students valuable traits like time management, punctuality, determination, self-control and perseverance. We at UrbanPro, understand the importance of exams in a student...

Read full article >

Class 10 is the first external exam in a student s life. It decides the admission process in future, as almost all colleges and universities grant a seat based on Class 10th marks, as one of the criteria. For students who plan to opt for science as their stream in higher classes, it is essential that they begin preparation...

Read full article >

Social science is a subject that requires a student to deal with facts about human behaviour in its social and cultural aspects. Unlike mathematics, science and geography, that test a student s problem-solving or analytical skills, social science are mainly about dates, terminology, battles, treaties and policies. Class...

Read full article >

Like Mathematics and Science, Hindi is also an essential part of the class 10 syllabus, which requires regular and sufficient preparation. Many students might mistake this subject to be an easy one and give less importance. If you want to score good percentage, remember that marks obtained in Hindi will also matter. They...

Read full article >

Looking for Class 10 Tuition ?

Find best Class 10 Tuition in your locality on UrbanPro.

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you

Find Best Class 10 Tuition ?

Find Now »

UrbanPro.com is India's largest network of most trusted tutors and institutes. Over 25 lakh students rely on UrbanPro.com, to fulfill their learning requirements across 1,000+ categories. Using UrbanPro.com, parents, and students can compare multiple Tutors and Institutes and choose the one that best suits their requirements. More than 6.5 lakh verified Tutors and Institutes are helping millions of students every day and growing their tutoring business on UrbanPro.com. Whether you are looking for a tutor to learn mathematics, a German language trainer to brush up your German language skills or an institute to upgrade your IT skills, we have got the best selection of Tutors and Training Institutes for you. Read more