Q) PA, QB and RC are each perpendicular to AC. If AP = x, QB = z, RC = Y, AB = a and BC = b, then prove that + = Ans: Let’s look at Δ CQB & Δ CPA, By AA similarity theorem, ∠PAC = ∠QBC (perpendicular to AC) ∠PCA = ∠QCB […]
Q) A ladder set against a wall at an angle 45° to the ground. If the foot of the ladder is pulled away from the wall through a distance of 4 m, its top slides a distance of 3 m down the wall making an angle 30° with the ground. Find the final height of
Q) Solve the pair of equations x = 5 and y = 7 graphically. Ans: Here is the answer to this question: For a detailed answer to this question, please refer to the following question and its solution: (click on the link on the question) Solve the pair of equations x = 3 and y
Solve the pair of equations x = 5 and y = 7 graphically. Read More »
Q) Prove that (cosec A – sin A) (sec A- cos A) = Ans: Let’s start with LHS: (cosec A – sin A) (sec A- cos A) = ( – A) ( – A) = () () = () () = cos A . sin A Now, Let’s solve RHS: = = =
Prove that (cosecA – sinA) (secA-cosA) = 1/(cotA+tanA) Read More »
Q) The centre of a circle is (2a, a-7). Find the values of ‘a’ if the circle passes through the point (11,-9). Radius of the circle is 5√2cm. Ans: Let’s find out radius of the circle by co-ordinate method. Therefore, (2a – 11)2 + (a -7 + 9)2 = (5√2 )2 or (4a2 + 121
Q) Using graphical method, find whether following system of linear equations x = 0 and y = – 3 is consistent or not. Ans: Draw graph for y = – 3 and x = 0. As y = – 3 is intersecting x = 0 at (0,-3); So, system of equations is consistent.
Q) Find the least number which when divided by 12, 16 and 24 leaves remainder 7 in each case. Ans: Let’s start with LCM of 12, 16, 24: We get LCM as 48 Since remainder is 7, It means the number is 7 more than LCM Hence, the required number is 48 + 7 =
Q) The discus throw is an event in which an athlete attempts to throw a discus. The athlete spins anti-clockwise around one and a half times through a circle, then releases the throw. When released, the discus travels along tangent to the circular spin orbit. In the given figure, AB is one such tangent to
Q) Can any rational value of x make the new area equal to 220 cm2 ? [ Click here for full question] Ans: If by increasing each dimension by x units, the area of the photo is enlarged to 220 cm2, then (18 + x) (12 + x) = 220 ⇒ x2 + 30 x
Can any rational value of x make the new area equal to 220cm2 Read More »
Q) While designing the school year book, a teacher asked the student that the length and width of a particular photo is increased by x units each to double the area of the photo. The original photo is 18 cm long and 12 cm wide. Based on the above information, answer the following questions: (i)