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Question : 30 of 90
Marks:
+1,
-0
Solution:
Given,
×=4⋅.....‌ (i) ‌×=9⋅.....‌ (ii) ‌×=α⋅...‌. (iii) ‌Taking dot products with
c,, we get
â‹…=â‹…=â‹…=0Hence,
‌ (i) ‌⇒||⋅||=4......‌ (iv) ‌(ii)
⇒⋅||=9⋅||.... (v)
(iii)
⇒⋅||=α⋅... (vi)
Multiplying (iv), (v) and (vi)
⇒||⋅|⋅|∣=36α.....‌ (vii) ‌Dividing (vii) by (iv)
⇒||2=9α⇒∣=3√α.... (viii)
Dividing (vii) by (v)
⇒||2=4α⇒||=2√αDividing (viii) by (vi)
⇒overrightarrow‌||2=36⇒∣=6Now, as given,
3√α+2√α+6=‌⇒√α=‌
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