8.2 1(i)(ii)

प्रश्न- 1 निम्नलिखित के मान ज्ञात कीजिये ।

(i) sin60⁰cos30⁰ + sin30⁰cos60⁰

(ii) 2tan²45⁰ + cos²30⁰ – sin²60⁰

(iii) cos45⁰ / sec30⁰ + cosec30⁰

(iv) (sin30⁰ + tan45⁰ – cosec60⁰) / (sec30⁰ + cos60⁰ + cot45⁰)

(v) (5cos²60⁰ + 4sec²30⁰ – tan²45⁰) / (sin²30⁰ + cos²30⁰)

(i) sin60⁰cos30⁰ + sin30⁰cos60⁰

हल -  

sin60⁰cos30⁰ + sin30⁰cos60⁰

√3/2 x √3/2 + 1/2 x 1/2

= 3/4 + 1/4

= (3 + 1)/4

= 4/4

= 1

(ii) 2tan²45⁰ + cos²30⁰ – sin²60⁰

हल -  

2tan²45⁰ + cos²30⁰ – sin²60⁰

= 2(1)² + (√3/2)² – (√3/2)²

= 2 + 3/4 - 3/4

= 2